I've just been through 3 days of a mix of pair-programming development, XP-style, and buddy-style problem solving (different areas of the codebase, natch). I'm having trouble believing how fast we're developing; even with about 40% of our time lost due to problem-solving, we're still about 50% ahead of schedule. I was even tinkering with a class we were inheriting from trying to make the new code work, all the time knowing I never broke any of its own tests.

Wade.