I've been ordering from Rainier since 2007 and I never had any problems with them whatsoever. They've always been awesome to deal with, shop with, and speak to. I had to make one return before and it was handled with ease and efficiency. I also ordered a custom assembled upper from them before and it turned out to be one of the best upper receivers I've owned.
Major props to John and his crew, I'd recommend them to anyone! And yes, lightning quick shipping!