Summary: I use this mat mainly for yoga, but every once in a while I also use it for P90X, which is heavy duty. I break into a sweaty mess 10 minutes into the workout, and the mat loses all of its stickiness, causing me to have to correct my pose every 15 seconds because my feet spin and slip out of control. Of course, this is a major inconvenience. So, if you sweat more than the average guy or girl, consider getting another mat. This one is otherwise very fine.
Summary: I'm not a super fitness buff and this is the first yoga mat I bought. I only use it at home and not very frequently. It serves its purpose well--it provides enough cushion and stays put on the floor. My only complaint is that if my hands or feet get even a little bit sweaty, they slip all over the mat so I've had to put a towel down and then it works fine.
Summary: I purchased a bunch of these mats for my yoga studio. My students complain that they are slippery, and the mats also don't seem to stand up to regular use; most of the mats have disintegrated after just a year or so of use.
Summary: This mat is only of standard thickness (1/8"), but it is the best 1/8" mat I have ever tried! The last 1/8" mat I had barely protected me from the floor; this one has a memory-foam-like quality, and really does a good job of cushioning me in comparison to the Hugger Mugger one I had last time. While a 1/4" might be squishier, this is a really very good 1/8" mat, and I was pleasantly surprised by the quality....