How slow are .NET exceptions?

Question

I don't want a discussion about when to and not to throw exceptions. I wish to resolve a simple issue. 99% of the time the argument for not throwing exceptions revolves around them being slow while the other side claims (with benchmark test) that the speed is not the issue. I've read numerous blogs, articles, and posts pertaining one side or the other. So which is it?

Some links from the answers: Skeet, Mariani, Brumme.

Answer 1

My XMPP server gained a major speed boost (sorry, no actual numbers, purely observational) after I consistently tried to prevent them from happening (such as checking if a socket is connected before try to read more data) and giving myself ways to avoid them (the mentioned TryX methods). That was with only about 50 active (chatting) virtual users.