I know Trevor Bauer uses the marc pro and is a very big proponent:
I know that Kyle's pro, college and HS pitchers use the Marc Pro and he's had great measurable results with it: http://www.drivelinebaseball.c...oducts/arm-recovery/
I've used it with my pitchers (disclosure: I won mine, and didn't buy it), and they all love it. Whether it's a placebo effect, I can't be sure. If the price is too much, I've also used the Stick on pitchers' Flexor Pronator mass [see http://www.ncbi.nlm.nih.gov/pubmed/15466738 ]. Before getting the Marc Pro, we used this: http://www.amazon.com/truMedic...f=zg_bs_8627079011_1 While not as nearly good as the Marc Pro, for the price, it's a good deal and seemed to help.