I took the opportunity to try TF2 with this free weekend and played for ~ 3 hours last night. I'll probably play it tonight and tomorrow until the trial runs out, but unless something magical happens in the next 2 sessions, I'm probably going to pass on buying it.
Only played 3 classes -- sniper, heavy, and scout. Did okay as a sniper, got pwned as a scout, and dominated as a heavy. And this was my first time playing this game. As a noob, my initial observation is that this game has serious character/class imbalances.
Don't know, but I would think if I wanted a frag fest, there are probably other games like UT3 that are better.