I have an Ouano long sleeve rash guard. It's ok, I wouldnt buy it again. The material and seams are fine, but the chest logo started falling off after a week. Also, it's not a turtle neck, but it still rides up a bit in the front. Not a huge deal, just bugs me a bit.
I have a cheap Wal Mart rash guard and I wear it more often. And you can't beat the price. I buy most of my stuff from Combat Sports International. MMA Warehouse, and Fightrack.com. Check them out for sales periodically.