I've been debating on getting that, but I never played the first COD very much. Is this comparable to that one?
Are you asking because you bought the first COD.. but ended up not playing it much?
I never really played the first COD, so I can't tell you that.. I can tell you that I've always preferred css over any other fps.. no other game has ever come close as far as registration / feel / movement (when you shoot a guy in the head, he dies.. etc.).. I think COD MW 2 (on pc) does.. and the added strategy (various game play types, additional weapons and equipment, various nades, etc.) that comes in to play and the perks/challenges make the game crazy fun.. plus, it doesn't get to BF2'ish... where you find yourself hiding in a corner while planes and tanks take over the game..
I'm AFK traveling for work all week.. if you want to demo the game for a couple days on my ID, shoot me a PM (keep in mind it's about an 11 gb DL from steam)