It has been posted previously on several occasions that MPC gets their chicks through Meyer. I know Meyer is doing a small order program as well, but they don't sell their bantams sexed which seems to be one of the main reasons people order from MPC.
I have had mixed luck with MPC. I had a rather minor issue and could not get any response despite multiple attempts over several weeks. This was over the summer when a few other people were having the same issue. To this day, they have *still* never returned any of my messages.
That said, the chicks I got were decent quality with just a couple problems. I got a couple of roos that were supposed to be pullets and a couple died, but nothing terribly out of the ordinary. The birds I was left with are higher quality than the typical hatchery (something to be said more for Meyer than MPC).
I may or may not order from MPC again. It would just depend on the situation. They impressed me as having ZERO customer service skills. I would order from Meyer directly though.