Is this question for when you choose a pump for a MK5???
APR all the way. Spend the money, get the performance.
This is all from my experiences using, fitting and repairing different pumps.
KMD - I have had loads of failures that have cost lots of money to fit. When they had the coating, they would sieze, break the follower and fook the cam. I hear they are better now they have done away with the coating, but their customer support was a joke.
Autotech - Not had a problem with these apart from the way they can allow fuel to pass through the seal and mix with the oil. Bad news for rings, bores and bearings. Personally, I have only felt the horrible 5.5k flat spot with the autotech pumps.
APR - fully built, tested and ready to go, great customer support too. Piston design wont put pressure on the seals and there is a larger surface area on the follow which seams to cause less wear on the followers. I have APR's fitted to loads of cars inc X-bows which are abused for hours on track days and are still perfect. Ive not had any pressure drops or flat spots on the cars ive fitted the pump to.