It just boils down to what you prefer!.. If you want a deeper sound then go with the H-pipe!.. If you want to be like me and have a slightly different sound then go with the X-pipe!.. I can't really say what may sound better with Flowmasters as I'm not really a fan of them!.. I have my reasons!!... Lol And because the system I currently have on my car is the CherryBomb Vortex system!..