So far it has been 100% reliable. I believe the folks that have had issues with feeding didn't replace the single stack type bolt with a double stack one.
The bolt on the right is a standard M70 bolt used with a double stack magazine. Note the lug on the bottom is wider than the lug on the bolt on the left. If you fit that lug into the top of a magazine it is the width of the opening.
The bolt on the left is the bolt that comes on the standard single stack PAP and the lug is the width of the SS magazine opening. In addition, the lug is about .060in. shorter on the left hand bolt. Combined, these two factors do not allow the stock PAP bolt to function reliably with double stack magazines.