Within such a short time, Thunderbird had a lot of really good character moments. I especially liked the Alpha Flight arc. Exiles was at its best when they took the time to look at how small decisions could make the biggest impacts that differentiate each universe.
As to the AoA universe, the depowering annoyed me at first but the story and character work was just so good. It's a shame that the crossover happened. Such a crummy way to end a pretty solid run.
Exiles is the only series where I own all the individual issues and trades.