I once met a classical guitar player who played in the key of D flat. When I asked why, he said he liked the "tember" of the key. He like those subtle tone combinations that result from useing a temper music scale. I will have to admit that some songs do sound better in certain keys.
Still, when jamming with a group, I consider it polite to stick with a key that is easiest for everyone. The middle ground for most instuments and voices are C, D, G and A. Capo's and tunings help with the rest.
Yea you right Jim. I've been rehearsing with my new Zydeco project at a centrally located studio in Midtown Manhattan once a week so it is a problem bringing lots of accordions. I have had to make do with just 2 singlenotes and 1 triple (which is still a lot to haul around) so I have been learning lots of keys. They do all have their own sound. I love playing out of the "D" position on a single row. You can get that plentatonic blues scale really nice on the pull.