I have a small alloy AB - well built and should last. A couple of (over-critical perhaps) comments.
1. The floor has a void which can be drained by a screw out bung. However, the only way water
can get into this void is through the bung itself - which it does every time it rains because there is no seal between the aluminim floor and the plastic housing - daft design.
2. I have noticed the smaller AB models tend not to plane very evenly. The bow bounces up and down. I've been in a number of sub- 10(ish) ft models and have noticed the same - Seems not to be a problem with those over 10(ish) ft (not sure of the exact model size where this no longer happens)
3. I have thrown away the seat - if the seat is in place the metal edge works away at the hyperlon - almost went through in about 2 weeks with me before I noticed and put a patch on. I have a friend with a larger model who has had his seat in place for more than 2 years (he uses it daily) and no wear - so looks like only a problem on some models (perhaps because mine bounces along and his is very smooth on the plane???)