Gives lots of good stats. I like the fact that you can tunnel down into the data in a few interesting ways to see for instance search engine "crawlers" vs. purported "real humans." Or you can burrow down to get stats on a specific day or a specific hour on a specific day, etc.
Haven't had any major issues with it, and it's given me some interesting insights into our company's site traffic patterns. For instance that search bots far outpace real human views... =o\
There are a few metrics it could add to be even better like bandwidth usage. (Please? If possible...) But other than that, it seems quite useful. I'd give it a definite thumbs up!