T.M. R540 is a beautifully constructed club. I can't think of anything negative to say.
This driver is phenominal!!! It has the largest sweet-spot of all the drivers I experienced (including Taylor Made 320). It sets up well and has near-perfect balance. My average distance went from 230-250 to 250-270, and I'm not a big/strong guy either. One more note: I chose M.A.S. 70 Stiff shaft whereas I'm more used to playing with Regular flex.
Bottom line is, you have to try this driver. If adding 20+ yards and accuracy to your tee-shot is worth investing $399, then go for it.