I don't understand why you're describing what 30FPS feels like when 99% of people here will have a had 1st hand experience.
I'm pretty bewildered by the unplayable comments mainly because if a game is good enough, you get into it and don't notice the framerate, atleast not as much. I can play GTA IV online for ages, I don't need fraps running to know the FPS is hovering around 30 at certain points but I continue to play and enjoy it. Certainly 60FPS would be better but I don't refuse to play or say to myself this is unplayable.
Same with Crysis Warhead and Wars, quite a bit of that is sub 60FPS, OK maybe not as low as 30 but still enjoyable let alone playable!
Only thing that gets me are FPS spikes, sub 30, which is uncommon when running a 5870 @ 1080p. Again, I look at the people here demanding 60FPS, do they actually have the hardware to back up that kinda framerate or are they lowering settings. Personally I go for a sweet spot, slightly favouring eye candy over framerate but then again I've always gone for "high end" hardware to get the best of both.
Can't really comment on competitive play as I've never played CSS etc at a high level. I totally agree on it varying from game to game, but on the whole, the very very good majority of games are playable at 30FPS. I also believe this an 'ignorance is bliss' situation...