Yeah, so far I haven't seen anyone really making this complaint on these forums.
The L4D Steam forums, on the other hand.......
Although the game isn't out yet of course!
Not that I think anyone will have anything to complain about when it is finally released though.
I played KF and loved it, then when L4D came out i absolutely loved ithat too and switched over to that for a while. It looked better and gave the impression it had fewer bugs. (Only an impression at the time... L4D is actually buggier than bug burgers).
Now, though, L4D is feeling tired and repetitive, and I find their lack of content disturbing. I've had my money's worth from Valve as I've clocked up a lot of hours on L4D... but it just doesn't have the longevity and variety that KF had. Also I'm finding it increasingly difficult these days to satisfy the following criteria for a good game on L4D:
1. Low ping (8 times out of 10 it's too high to be enjoyable). I'm fed up with having to spend 30-40 minutes going in and out of servers just to find a good one. Oh and the matchmaking system p**ses me off.
2. Players who don't quit. (I don't believe in 'ragequitting'. It's not the player's fault if he needs to quit. The game design/balance is bad, because 1 or 2 ppl quitting leaves the whole team screwed. This doesn't happen in KF so much)
3. Finding enough people online who are 'good players' to fill a versus or campaign mode server. Without good players it's impossible to have a good game on L4D.
Also I would now quite like to play a map that I haven't played 1 billion times before, and survival mode just feels like a 'mini-game'.
I could go on but you get the idea.
So I really loved L4D. The art. The style. The gameplay. It's just that it's so linear and 'prescribed' that the variety has gone, and as a result I'm just bored of it.
KF is different. Very different. I don't think it's possible to get bored of it.
I think it's actually got to the point now that even when the SDK for L4D comes out... it'll be too late. I'll be playing KF most of the time instead by then!