One benefit to the Project X1 is that the arm has adjustable VTA, whereas with the Rega one would need to use shims for VTA adjustment if not using Rega's line of cartridges. I personally would never buy an arm without adjustable VTA. The Project arms, while nothing special, also have low effective mass, so one could use them with high compliance carts (e.g. vintage MM) so there is more room for exploring different carts on the Project. All that said, I used to have a Project Esprit(?) and it sounded just okay, with bad isolation from itself and the environment. Moved on to Clearaudio not long after that.
