At that time, I got both COD4:MW and the OB for the pc and It was the best holidays I had in my gaming history. I bought the OB for Half-Life mainly, so Portal and Team Fortress were like 2 big bonuses and suprsisingly they were amazing (especially Portal), then I played MW and I was blown away by both the single-player campaign (wich I think is better than MW2's) and the multiplayer (I can't compare that to MW2's).
I played a good chunk of TF2 and I liked it, and I saw a lot of potential life sinker on that game, but I was more entertained by MW and I played more MW than TF2. I like team-based multiplayer games (I still love both L4Ds), but I simply couldn't stop playing MW, even if it wasn't as supported and patched like TF2.
Today, I don't play both games as I used to, mainly playing TF2 if a new patch goes live to see the new quirks, bells and whisltes added to it. So, no, I don't consider TF2 outdated, it's still a very fun game and Valve patches the game a lot and regularly, there's even a lot of classes left to patch and Valve are planning on adding a lot of new features, weapons and achievements. CS:S, by the other hand, is the definition of outdated, they haven't patched that game like since 2005 (only adding minor stability patches like every 9 months or so) and MW since the beginning of 2008.