Generally it's those with higher alcohol contents. I doubt anyone would want to drink a Bud Light from 2007 ;)The only one's I've aged usually have a 5 year window. I just saw someone recently mention they were doing a tasting of 20 straight years of someone's seasonal, would have made for a fun night.
By BA ratings those are all really good beers. I've only had the Zombie Dust personally.
Btw, the Zombie Dust is the #12 beer in the world according to BA - link may require a free account.
I'd do the trade personally since he's offering a variety of good beer and you said you didn't particularly like them in the first place. Plus you'll still have 2 left.