virtually HL is supposed to be limited to something like 600 poly per character, but even if u do it 1200 poly that would still work on todays computers, models in esf are about 1200 poly. so u don't realy have to worry much about that!
The HL limit used to be 3,000 polyies per model, actually. Only now there's a way to avoid the poly limit, and pretty much even exceed 5,000 if you want to, even with 512x512 meshes. It may very well not be that wise to go that high though, since this -is- a beta, and it could cause some serious probs in-game. i.e. crashes
Especially with people who have ****ty comps. (unlike me)