As you can see in the class selection in Red Orchestra 2, you are limited in each class and by all means, the game is still intense no matter what class someone picks. I know that RO2 and TF2 are very different games but you get the idea. Now, I know some classes shouldn't be limited like Soldier, medic etc. but we can limit on heavy,engi,sniper,demo, and spy because those classes in high number are pretty iffy IMO. Even with only 2 slots as sniper in RO2, there was no interest in the class with only 1-unlike TF2 where 90 percent of the time there is 2+ snipers or spies.
As far in RO2, when other classes are full, you are stuck as Rifleman (my personal favorita class) so i am not affected. But like who has a slow Hard drive and will take longer to load maps, or come in the game late, I will not get to pick my favorite class because they will be full like sniper. So I could go both ways when it comes to class limits.
(http://cloud-2.steampowered.com/ugc/903255624302364046/CEEB83708D7E03B913674F5F77DF021960114E45/)
Admin Edit: Resized picture.