I do flip houses and use Schrock cabinets and have never had a big issue. Like anything that man makes some things come in damaged. It has never taken me more than a couple weeks to get the replacements. I decided to put them in my personal house and my wife loves them, so much she doesn't want to move again unless we put Schrock cabinets in.
I can tell it does make a difference the quality of who you buy the cabinets from and who installs them. Therefore if you are having a problem it may not be the manufacturer but the dealer.