I still think it's a strong and fairly durable material, but if I were in the market for an aluminum boat, I would explore their repairability with someone who welds the material.
I weld aluminum. I used to make cash for partying welding aluminum water heater tanks from RVs. Here in the northeast the RV dealers do a brisk business replacing those things when they freeze! I'd stop by a dealer aand pick up 10 or 15 tanks split wide open and get $30 a piece to weld them, and I guaranteed they wouldn't leak. Took me about 10 minutes a tank with Tig torch. So I definitely wouldn't worry about getting an aluminum hull repaired. Aluminum is actually easier to weld out of position (overhead, vertical) than steel because it less dense and doesn't sag as much.
Take a look at the Yahoo! Origami boats newsgroup. A VERY clever way to build a metal boat. I sailed on a 36 footer in steel out in Seattle. Sailed upwind like it was on rails, almost no effort to steer.
Gary H. Lucas