I own a Brompton M3L (3 speed hub, all steel, traditional handlebars) which I purchased about a month ago, and typically ride a) from home on the Upper West side to work downtown on the Hudson River bikeway and b) on weeknds in Central Park. I'd say I've ridden it over 100 miles and am very happy with it.
Today I visited the Times Up! Folding Bike Festival in NYC. David from bfold.com was there with a couple Tikits, and I talked to him, rode it, and compared it folded and covered to my own Brompton.
The Tikit is a very nice ride. I like my Brompton ride; what seemed at first "twitchy" compared to a full size bike, I now think of as manuverable & responsive. But the Tikit feels smoother. More like a full size. It is just better.
I didn't really understand the comments about Brompton brakes until that ride. I think the Brompton brakes are satisfactory. But the ones on the Tikit are waaay better: more powerful and easier to modulate as well.
Weight seemed about the same. Folded size is definitely both smaller and more regular (i.e. "square" with no parts sticking out) on the Brompton, but it's not a huge difference. If I was on the subway, I'd rather have the Brompton. It's just a lot less likely to catch on people. But now that I have the bike, my subway ridership has fallen off a cliff...I've even purchased gear to ride in the rain, I like riding so much...
I don't think either is better; they're different.
If I was getting a folder mostly for taking up little space and throwing in my car, and I lived in a not-always-flat area, I'd probably go for the Tikit. It's not much bigger than a Brompton, and the ride is nicer, and there are 8 gears. It feels like they've put a lot of thought into the design, down to the details. An example of this that isn't immediately apparent is the integrated bell. It's brass and has a beautiful ring. They didn't have to do that. And yet, they must know (as any good cyclist does) that a bell is really a must have for a bike used in cities - so why not integrate it.
If simplicity, reliability and friendliness with multi-mode transportation were relatively more important - I think the Brompton still wins. The Brompton design has been around for years now. So though some of the bits seem less nice than they feel like they should be for the price, they work. With the Tikit, you're taking a bit of a risk that the design and componentry will hold up over time. For exampe, apparently Bike Friday's SatRDay folding recumbent was recalled a couple of times for problems. I don't mean in any way to smear Bike Friday; I certainly don't know the details. I'm just pointing out that with any new design, you give up some certainty reliability for the improvements.
One thing I expected to be a clear advantage for the Tikit, that I don't think is, was the ability to roll the bike folded. Rolling a Brompton folded isn't all that serviceable. I mean, good enough for pushing around at slow speeds - say in a store - but not for any appreciable distance. I expected the Tikit to excel in this regard, with its built in handle and ability to roll on the front wheel. However, as David pointed out, and I confirmed for myself, the bike's weight folded does not center over the wheel, so you need to exert arm strength to keep it balanced while rolling it around. Absolutely do-able...just not as nice as I'd hoped.
Your best bet is to try both. If NYC is not inconvenient for you, bfold.com would be a good place to do it. David (who I only met today) seemed like a great guy to spend $1K plus with. I bought my Brompton from a place that was ok, just, I think, a little less personal.
In any event, I think both are great bikes. I'd like to own both.