Good overall review .. but theres a few things that I have to disagree on ...
I have played CS 1.3 to 1.6 (if I recall correctly) and here are my thoughts about the transition based on the points I would have had different oppinions on :
The footsteps : The footsteps for me on CS:S are extremely sharp and precise, to a certain extent you can be called wallhacker (you know, the little kid who didnt get the trick yet and wonder how the fuck you turned the corner and opened fire to harnest a direct headshot). So maybe its hardware related or something else ... My sound is usualy cranked pretty high, and I wear noise-canceling headphones on a 5.1 card, might help

The GFX : The game for me doesnt even need AA and AF, simply because Ive never played below 1920x1200 in resolution

At that ress, even if you slap in some filtering, you wont see the difference (for techies that get nosy : I play on a WUXGA screen of 16:10 ratio

)
The headshots : I personaly have a very big graphical and sound feedback when I get a headshot... Theres a huge spark followed by the same sound a watermellon would make if you stabbed it with a screwdriver
I do agree about the frags though, sometimes they do feel a bit less interesting... As well as the darkness of the maps, which can be annoying sometimes...
Anyway keep it up !