Inexpensive, but not so hot
I feel the need to break with the field here. The Mad Pad was my first crash pad about five years ago. I never bought another, though I've known at least three people with the same pad. It is, indeed, very cheap, which is what makes it so attractive for new climbers. Just know that you'll get what you pay for. The foam seems to get stomped down in about half the time of most other pads. The stitching, fabric and straps can also break down relatively quickly. From a functional standpoint, I've found that these pads are annoying if you're padding blocky landings - it's like trying to balance a piece of plywood - and because it is so stiff, falling on this pad from high problems actually kind of sucks, at least until it's stomped out, at which point you may as well be landing on a sleeping bag. And it's not like any crash pads are comfortable to carry, but the strap design on this pad (along with the unyielding rigidity of the foam) hurts my back on long approaches quite a bit more than any other pad I've used.
If you're really strapped for cash or if you boulder only a couple times a month, the Mad Pad is certainly better than nothing, but if you're serious about bouldering I recommend spending a few extra bucks on a pad that'll last far longer and really hold up when you need it.
Three stars is generous.