I've heard nightmare. And I've also compared it side by side with the self titled previous album. The rev is a great drummer. But he's no portnoy. MP adds so much more detail and intricacies to the drumming that the rev didn't have. It sounds like MP came on to show fans of A7x how it should be done. No disrespect the the late, who gave as good as he got, and that was also very commendable. But MP made the album sound very enjoyable to listen to.
MP didn't join A7X, but now has more time to spend with them and other projects. That's a good thing, because the Nightmare album sounded like just what he needed!
That said, I'm very excited for the DT guys now. Think of what happened when Kevin Moore left. Then Derek sherinian. Then jordan's entrance. And when James labrie joined the band. You had one killer album after each of these incidents. Now, DT with a new drummer is going to be another killer! I can't wait!!!
But its also amazing how much Syn sounds like a young Petrucci in the new album! I highly recommend a listen!