I used Mint.com awhile back (probably three years ago), when it was still in a growing phase.
I liked it. Since data is downloaded automatically from your bank account (and other accounts - credit cards, traditional investments, etc) and categorized automatically, its great at automating most of personal finance. All debt information was laid out really really well, Income vs Expenses was clearly viewed, and if I recall, they even had a tool to auto create a budget for you based on past expenditures. It was quite user friendly. I don't recall a lot of in-depth analysis, but it covered the basics well.
I stopped using it because, at that time, they still were creating relationships with creditors to allow them account access. A few of the entities that I had accounts or debts with weren't on the list, so Mint.com couldn't download my information from them. And if Mint couldn't grab ALL of my accounts and information, then I had little use for it.
I've heard, though, that they've come a long, long way in this regard. I've considered giving them another shot recently, but I've fallen too much in love with my Excel budget.
Good luck.