I believe the three months was worth the equity, and we're still able to call on them when we need some advice or an introduction. My only hesitation in recommending YC to any relatively inexperienced entrepreneur would come from the increasing size of the programs...but I'm a serious introvert and I don't like crowds, so I might be judging the impact it has incorrectly.
But, it's hard to argue that YC doesn't have a very real positive impact on the companies it funds. The success rate, given how early they invest, is quite high so far, and the biggest successes are yet to come.
We weren't 100% sure going in, but coming out can say it was absolutely the right move.
In the best case, you're Xobni or Loopt or Reddit or Scribd. Seems like a no-brainer.
(Summer 07)
Worst case scenario, you'll learn a lesson or two the hard way. But they're going to be some pretty great lessons, and you're going to meet some pretty great people along the way. (MightyQuiz, winter 08)