I've been twice to Galax (2000 and 2002) and really enjoyed it both times. It's great for a a British old time player like me, because in a three week holiday I can do Clifftop then Galax then the British Summer Camp at Peterborough, so it's three weeks of really good Old Time till my teeth start falling out. Unlike Clifftop, Galax also contains a lot of good traditional bluegrass, but if you want solid Old Time (like me) you can find it - last time there I got to jam with the great Benton Fippen and Richard Bowman (of the Slate Mountain Ramblers). Folk there are very friendly, and mostly local to the area. I think when they judge the competitions the first thing they note is which county you're from - if you're not local, winning is a lot more difficult (IMHO). This of course doesn't bother me, I'm not there to win, but queing for the competition can be a lot of fun, with some great humour. If you take part in the competition and do all your stage appearances you get some of your camping fee back.

If you're camping in a tent get there early and try and find a spot above the level of the field. In 2000 we got 4 inches of rain in 4 hours which turned the site into a 6 inch deep lake. The trailers and RVs (who always get there early) were fine - the locals are used to it. You can pay to get a shower in the nearby swimming pool, or you can use the sports field's single free very cold shower, which is either fire engine strength or off. There's never a queue!
I've never seen the singing competitions, so I can't vouch for them, but the instrumental ones can be very entertaining (and also very bad). If you sit there all day you'll see some really great people randomly interspersed with some truly awful acts - but the audience is always great to them all - even you if you get on stage!
I'll hopefully be there in 2008, with a fiddler and a good guitar player, but this year it'll be Sidmouth which is on the same week.
Cheers
Ray