I should say at the outset that my comments are directed mostly to the use of a trailer for utility purposes. I do tour, when I have the time, but I have panniers for that. I will say some things about the trailer for touring purposes, too, though. Because the people interested in trailers on this site tend to be in the Touring Forum, this is where I decided to put the thread.
The mission profile: carrying oversized, misshapen, and very heavy items for many miles, trips that would otherwise have to be taken with a car. I wanted to use my bike even more for longer trips out of town than I do now. I already shop with panniers, but it would be nice to have even *more* room, especially to buy large bundles of paper items, electronic things, small furniture, or other household items that wouldn't attach so easily to the bike and rack alone. A secondary consideration would be to use the trailer for camping.
An acquaintance of mine has a Bob trailer, so I am able to make some direct, albeit incomplete, comparisons with a Bob.
You can find Burley's own description of the Nomad, with pictures, to supplement my account, here:
The Burley Nomad is a two-wheeled trailer. It is made with aluminum tubing, with heavy canvas stretched from the tubes to form the body of the trailer. Like Burley's child carriers, the Nomad can be taken apart. The sidewalls can be removed without tools, as can the canvas front piece, the tailgate, and the top aluminum crossbar. So, the trailer can be used as a flat bed trailer, a covered fully enclosed trailer, or any permutation in between.
The aluminum and canvas construction is surprisingly strong-- I've already carried heavy items like a generator, weights, and tools without any problems-- yet it is light. Someone worried about ripping the floor with an especially dense or sharp item could cover the floor first with cardboard or plastic. So, though I wondered about it at first, overall I think this is a better design choice than the metal construction of a BOB. It saves weight, for one thing. For another, the whole trailer breaks down without tools (the wheels and axles can be removed from their housing by opening a quick release), and can be packed relatively flat.
Burley claims the trailer weighs 14.5 pounds empty, and I would say that's about right. Burley says the trailer can carry 100lbs, and I'm sure they're right about that. I've carried that much already. In fact, though don't tell Burley, I've slightly exceeded that load for short trips. (BOB, by comparison, is rated only for 70lbs.)
The interior space of the trailer, when fully enclosed, is 32"L x 18"W x 15"H. As I mentioned, though, the top, sides, or any combination can be removed, so these dimensions are not a limit on the volume of the trailer. The trailer has 16" wheels, and sits about 23" off of the ground at its highest point. The overall width of the trailer, including the wheels, is 25".
The cover has a closed canvas strap for blinky, and the trailer comes with right and left rear reflectors. It also comes with a safety flag.
It's an attractive trailer when it's all put together.
Attaching the trailer:
One of the things I like about the Nomad is the attachment hardware. No modifications to the bicycle are necessary. The trailer has a rigid aluminum arm that attaches on the left side of the bicycle, at the junction of the chain stay and the seat stay. Attachment is by means of a plastic hook and hardware assembly, and can be done in less than a minute without tools. The attachment itself is very secure,and has a canvas strap with a clip that loops around the chain stay for a backup.
The trailer-bike attachment swivels in two dimensions-- horizontally, and in yaw. This means that that the trailer doesn't tilt with the bike. So, since the trailer has two wheels, only the bike *has* to be supported to attach the trailer, and the trailer can be attached fully loaded. In fact, the trailer can even be attached to the bicycle with one hand, once you know how to do it. So, you can attach the trailer without there being anything to lean the bike against. You can balance the bike with your left hand and attach the trailer with your right hand. I guarantee you that if you use the trailer much for utility purposes you will find this convenient.
Attachment is better than the BOB, which is more difficult to attach to a bicycle. Since the Bob leans with the bike, attachment requires that at least the bike be supported. The BOB shouldn't be attached fully loaded, either.
One point of worry I have: the yaw swivel occurs by means of what I think is a thick piece of rubber which can take some twisting. (It's inside of the aluminum tubing, so I can't be sure). How long will that last? I know Burley uses a similar design on its child carriers, though, and those have a good reputation for longevity, so I won't worry too much about that. Burley recommends replacing the hitch every five years, so I assume the rubber bit is designed to last that long under normal use. Burley also warns against using the trailer when it's below freezing, precisely because of the worries about this rubber attachment. That would be a fatal drawback, if you wanted to use a trailer in freezing weather.
One especially nifty point is that the trailer can attach to many bicycles that have a large rear rack. I can attach my Nomad to my 520 with its Jand Expedition rear rack, and can even use the trailer at the same time as my Arkel rear panniers. There are no problems.
Burley sells a skewer attachment for non-standard bicycles, like recumbents or others with weird rear ends, but the standard attachment should work with just about any standard diamond frame bicycle, even with a rear rack.
Riding with the trailer:
The trailer rides very smoothly, with good manners, and always in a cooperative spirit. Even if the trailer is *very* heavy, the bicycle's handling is almost entirely unaffected. Because the trailer doesn't lean with the bike, it's possible to rock back and forth while climbing, or to lean easily while turning. Furthermore, since the trailer has two wheels, the trailer wheels bear nearly all of the weight. Burley says that the tongue and rear bicycle wheel bear only 10% of the load, and I think that is about right from my experience. So, even with a 100lb load, the rear wheel bears only another 11.4 pounds of weight (load plus trailer). This makes the heavy use of the trailer *and* rear panniers possible.
Furthermore, the trailer doesn't develop any weird wobble, or an uncertain feeling in the handling with loads over forty pounds or so as single-wheel trailers do. The trailer does develop a subtle push-pull with a very heavy load, as you accelerate, but that doesn't place the handling in any jeopardy. It just provides an extra sensation.
It is the greater stability, the better handling, and the greater weight capacity that are the strongest advantages of a two-wheeled trailer compared to a BOB. These properties are why I bought the Nomad instead of a BOB.
The trailer *can* tip over, though, unlike a single-wheel design. If you take turns at reasonable speeds, though, this is not a danger. Burley recommends you take no turns at faster than 5 mph, but I've taken full turns at 10 - 15 mph with the trailer with no problem. I would recommend turns closer to 10, though, with a heavy load. Snaking turns can be taken faster, of course, and hairpin turns should be slowed for.
As I said above, the trailer is about 25" wide with the wheels, so it is a bit wider than the bars on a touring bike. Thus you have to be attentive when you are clearing tight passages. Still, the width is not excessive, even for riding in traffic (which Burley, no doubt moved by the legal department, says they do not recommend). My frond end is about 25" wide when my Arkel panniers are on the front rack with any kind of load in them. I have never worried that the bike is too wide to be ridden even on narrow roads with my panniers, and I've never found myself wanting to ride through an opening I couldn't, so the trailer is no additional worry in that regard.
In fact, though, the trailer gets attention from motorists, with or without the flag. Drivers give me extra room with the trailer attached. Even if it were wider than what I've ridden with already, I wouldn't worry about it myself.
The trailer is not centered exactly behind the bicycle. It is slightly to the left. This is a good thing, and another example of the thoughtful design at Burley. Riding as you normally would on the edge of a narrow road, with a ditch on the right, perhaps, the right wheel stays on the pavement. This lessens the danger of the trailer leaning off of the road, and possibly tipping over. This is yet another product of Burley's child trailer design, I'd wager.
For very narrow passages, or to reduce the wind to a minimum, the BOB would be a better choice. So, if you weren't carrying much load, as when touring, a Bob might be a better trailer. If you were going to tour on narrow paths offroad, I would not recommend the Nomad.
The Nomad has a waterproof cover, but there are gaps in the canvas of the corners of the trailer. These gaps allow you to manipulate plastic joining clips that reinforce the attachments of the sidewalls. So, the trailer is not fully waterproof. Plastic bags would be the order of the day if there were heavy rain and you had to keep things inside dry.
I think the Nomad is clearly a better trailer for utility purposes than the BOB. Its ease of attachment, better handling, and greater weight capacity all outdo the BOB.
I wouldn't hesitate to use the Nomad on a long road tour, either, though here the width of the trailer is a disadvantage compared to the BOB. If you were going on a long road tour, I think the BOB would be better. For dual use, I think the Nomad is a better trailer.
The BOB and the Nomad are about the same price. I got mine for $280, which is what BOB Yak goes for around here, too.