I've held off playing the multiplayer until I reached Blackwater, and I'm now considering trying it. I have heard that it has been unstable, has that changed and is it now a good time to check it out?            

been smooth as silk for me though I've only been on it a couple of nights for a few hours each. I've personally really enjoyed it, much more so than I did with GTA4.

I find it really fun. I haven't tryed any of the actual competitive modes yet, though. I've just been screwing about in ma ''posse'' fighting gang hideouts, doing random crap or engaging against other posses in the lobby. The overall world is a little barren though, and the respawns can be a nuisance with how close they send you. If there's some twat who's constantly just trying to get on your nerves, killing him will still have right back in a couple of minutes. Then again, that's what the private lobby's for. 
 
Soo...overall...fun. 
 
Technically speaking it's been fine for me on the ps3. 

can hardly ever get into a game and loading takes ages

" @Abyssfull: Sounds good, can you have a fistfight on the roof of a moving train? "

It can get a bit annoying, but I annoy other people just as much so I don't really see the problem. The competitive modes are really good also.

" been smooth as silk for me though I've only been on it a couple of nights for a few hours each. I've personally really enjoyed it, much more so than I did with GTA4. "