Anyone used Delving Deeper?  How does it stand up?

I've been looking for a cleaner version of OD&D (I started with Moldvay/Cook back in the day, after being introduced to the hobby with Holmes) that I can build on.  It looks good to me so far, but I was wondering if there were any unseen pitfalls I should be aware of.

I thought you were asking about spelunking...haven't  heard of a game called that.

Really interesting OSR game that has a few different takes on some of the sub-systems. I dig it, as their entire rules document is a living doc online:

http://ddo.immersiveink.com/dd.html