Flowmaster X kit vs Pypes X kit, any experience with fitment?

Mine is a 440 with Schumacher Tri Y's, so between the X and the header boltup it will have to be custom anyway. I am more concerned with the rest of the system and how it hangs/clears/etc. I have heard issues with the Flowmaster tails not sitting correct and not being long enough to cut off the silly downturns so tips can be used? Not sure what forum. I always use X pipe. not worried about the power loss, the Schumachers are already killing so much an X won't matter. It just sounds so much better to me