I have the front Jandd Extreme rack.
It fits the LHT nearly perfectly. The platform is longer than the one on the Surly Nice by an inch. Still, it's not as much platform as you may have imagined/wanted.
The rack is made of solid Al rod, like all inexpensive racks. It's strong enough, but also heavy. Mine weighed 1030g without mounting hardware (significantly lighter than the Nice rack btw). The newer (2003? onwards) have the rack shortened to provide more space for fit/front brake. On the older ones, the platform extends all the way back. Jandd still uses picture of older model on their website. Current model looks like this:
http://www.amazon.com/Jandd-Extreme-.../dp/B000RKBAJI
The platform area is 150mm x 250 mm.
On my bike, I fix a rear trunk/racktop bag (big rectangular boxy thing) to the front Jandd rack. It fits pretty good and makes a nice alternative to a handlebar bag. The rack platform isn't really big enough for attaching large items (fork/headtube gets in the way) , so the racktop bag gives me more storage space while saving me the cost and fit complexity of a handlebar bag. On a <52cm LHT, if you carry much on the platform you can't hardly fit a handlebar bag anyway, depending on your bar height.
I like the large platform of the Jandd Extreme rear rack (longest rear rack you can buy
AFAIK). It is heavy (but lighter than Nice rack). The problem with this rack is that it encourages you to load in such a way as to predispose your bike for shimmy - specifically by hanging a lot of weight high and far back behind the rear axle. The rack acts as a lever that tends to induce shimmy. Ideally you want all the load within the wheelbase for best control, however this is usually not possible. But loading high and rearwards should be avoided as much as possible.