I do like COD2 multiplayer, but I still get more enjoyment from RTCW:ET. One of the main reasons is that RTCW:ET has class-based, objective-style play which promotes teamwork. I find that COD2, while it does have several different gametypes, is just a bit too chaotic and repetitive. That being said, the fantastic graphics and sounds in COD2 make it a truly immersive experience. IMO, it feels more realistic than any other WWII FPS game (not that I know what it was truly like). For that reason, I continue to play some COD2 multiplayer, mostly CTF since I think it involves the most teamwork.
I also feel that the COD2 engine is such that there will never be a huge spread between the average players and the great players. Aiming seems a bit weird to me, and in my experience anybody can kill anybody very easily. You don't see insane K/D ratios in COD2 like you do with games based on the Q3 engine. Maybe that's a good thing to some people, but I don't really like it. I like the fact that in RTCW:ET, a newbie has absolutely no chance of killing a skilled player in a SMG dual.
PS: You actually like that red-dot aiming mod? I find it extremely annoying. That's why they have down-the-sight aiming mode.