Transmission availability and wheelbase seem to be the biggest differences.
The short bed double cab is available with either the 6-speed manual or 5-speed auto. The long bed is only available with the 5-speed auto.
The long bed has a longer wheelbase. Advantages of this include better weight distribution when adding load to the bed and a smoother ride at the expense of a some turning radius and breakover angle, as mentioned.
I believe the short bed has the same wheelbase as the access cab, so the rear axle is located pretty far forward in the bed. This can magnify the weight transfer of heavy loads in the bed or heavy trailer tongue loads if towing. The rear axle in the long bed is pretty well centered in the bed.
The long bed is a more standard bed size for compact trucks, so the availability of shells, campers, racks and other bed-specific accessories is better.
Having a short bed, I can tell you that I've loaded the truck to the gills and the weight balance is fine in the short bed. The long bed will probably tow better.
Also, there are tons of accessories for both the long and the short bed. The Tacoma is crazy popular and there is deep aftermarket support.
The short bed will be easier to maneuver offroad. I would not buy a long bed if planning to do anything moderately technical. Yes, the long bed is capable. But there have been times where I've been in tight situation and barely made it through without damage. I can't imagine how that would have gone with a longer vehicle. The short bed is definitely the longest vehicle I would wheel. If you're only driving forest roads, probably not a problem.
Consider that the offroad model does not come in a long bed. You can get a TRD sport in long bed, but no locker, no progressive springs, and no upgraded brakes. And maybe no ATRAC. (sorry, don't remember).
Sent via fat thumb