Just installed a new prochamber on my car last night and I had and x pipe on my last car. Both sound really good and much better than stock. However, I really miss that x pipe sound. It just sounded more aggressive at WOT and wasnt as 'droney'. I had flowmasters with it too and it wasnt all like the rumors you hear of x pipe/chambered mufflers. It may not be what all people like but I thought it sounded mean as hell. For what its worth, I'd go the x pipe route if I could do it again.