I researched long and hard before I invested in a yoga mat. For quality mats, my choice came down between the Manduka PROlite v. the Jade Harmony. Both are 3/16 thick and weigh about the same (Jade is heavier by 1/2 lbs). I ended up buying the Manduka Prolite Amore because it was cheaper, closed-cell (less bacteria, easier to clean), and has a lifetime guarantee (for the amount of money, I want a mat that lasts)! When the mat arrived, like the other reviews indicated, it was super slippery (there was non-existant smell; it didn't bother me). I gave it three or four washes in the shower, coarse salt scrubs, and 3/4 uses per week with mat cleaner wipe downs. After two months, it is less slippery than it used to be HOWEVER I still slip on it in a vinyasa/power yoga class. I don't consider myself to be a heavy sweat-er, but my feet and hands slip during most poses and I have to constantly search for "dry" space on my mat (I almost always slip/fall to my death in wheel pose). The constant slipping has caused unnecessary strain on my wrists to keep my body in place during various poses.
If you sweat minimally, Manduka prolite is a great mat - great colors, lasts a long time, and feels very study/great cushion during practice. However, if you sweat at all during class, I highly recommend going the Jade route. I just returned my Manduka and purchased a Jade - yes, everything sticks to it, it is open celled (greater risk of bacteria accumulating), and has a strong rubber smell in the beginning - but no slipping! A silp-free downward dog feels heavenly after months of constant readjustment on the Manduka. I'm not sure how the Jade will hold up with constant use, but it is the mat my studio recommends and even if it breaks down after 1 year of use, it is probably a good idea to get a new mat (if purely for hygienic reasons). While yogitoes might solve my slippage problem, it also has grip-to-mat problems. For me, I'd rather focus on my practice than focus on not falling.