Whew that's nasty. While I've never had a ping that high in my time with Left4Dead 1 or 2, I've been matched up with groups of people where we'd all have pings of 150-300. Those pings range from just barley playable with a noticeable delay that you can somewhat compensate for to hardly worth trying with a delay that makes it impossible to survive.

It's such a shame that peer-to-peer multiplayer is being put in more and more games lately. I'd rather not drink the kool-aid that's served (ex: Modern Warfare 2 or Xbox Live peer-to-peer claims). I can understand some conveniencewith it, but I don't think things like mods, customization, server communities, and good pings are worth losing.

I have never seen it that bad in L4D 1/2. 0_o