How does the game render the models that you view? I.E. What is the max distance that I can see a player in the game? I tried testing that with some of the grunt models, and they disapeared long before i thought they would. Is the limit a like a flat plane that extends parallel to your computer screen? Or does it curve like a sphere? I would test it with a LAN game but Installing Half-life wouldn't get a warm reception.

There is a max_viewing_distance you can set in your map properties, my best bet is it that, that controlls how far away you can se them...