I have the Race Lites and a buddy just got the X-lites. He let me borrow them for a long ride last weekend.
I would make that trade in a heartbeat. Performance-wise, there really isn't a huge, earth shattering difference - the X-Lites "feel" a bit smoother and lighter - but aesthetically, the new X-Lites ROCK. They are absolutely gorgeous to look at.
Don't get me wrong, I love my RL's. But for a mere hunge, I'd do it very quickly.
55/Rad