I’ve been using Adobe for about two years alongside FCS3. I really like Premiere and CS5 really raised the bar. To be honest I don’t think FCP7 was really all that good, but I’d be accused of heresy by some of the editors I know for saying that. The rendering delays were horrendous and compressing all your footage to ProRes in advance didn’t always make this better either. Especially if you’re using complex effects, text work, or transitions. I use a lot of text in our docos and the FC text tool couldn’t cope. So, in the last year, I’ve been using CS5 for about 75% of my work because it’s just more efficient. Although FInal Cut had some advantages too. Color was such a great program and the smooth cam filter worked very well for us because we do a lot of filming at sea using shoulder mounts and steady cam. The Smooth Cam was able to iron out some annoying rolls on good shots. Much more quickly and effectively than motion tracking in After Effects.
I’m not so familiar with Avid, but I suspect it is probably the most powerful tool, but the the most difficult to master. I have used Avid and I like it, but never had the time to fully master its potential.
Most of the TV guys here in Australia either use FC or Avid. Premiere is still considered something of a toy, which is unfair. With FCPX the game has changed. Final Cut is history. CS5.5 is capable of doing pretty much everything that Final Cut did. CS5’s suite is great value for money and a powerful suite that will enable you to create some seriously professional work.
It all depends on what you need. If you want a good looking resume I’d say use Avid. If you want to get on with your editing get yourself adobe.