When I get it I will probably just try it out, get used to the controls - if I can even run it. Is it the same as trying to run a Valve game with the highest settings? For example, in L4D if I set my shader settings to Very High, I will crash because my specs can't handle it or something. Or is rendering the final animation or poster the same as using the TF2 Replay editor?
Anyways, I'll just get the hang of it a bit then wait until it supports Left 4 Dead.