Since this thread has turned out to be a MM discussion, i'll add my two cents.
First of all, yes, Mike wants to keep everyone happy and try not to be pushy as far as his demands are concerned, he has admitted that. And i'm sure that all this time in DT he wanted to keep the band together and not be another MP to push things too far.
On the other hand, he is not very happy with his sound on ADTOE, he specifically said to me that his interpretation of the sound is like being recorded with just two mics. And i couldn't agree more, a lot of stuff is hidden behind the horrendous production, which is not his responcibility but mostly JP's. And the snare sound on DT12 was also not his decision, but he decided to go forward just to try something different, and respect the producer's vision.
Given that, when i told him about BTFW, in terms of sound and in terms of playing-intrepreting older parts, he told me that he feels more comfortable and he now feels free to be more like himself, since he has been accepted by most of the fans, and he doesn't need to prove himself anymore as being capable of keeping the band sounding like Dream Theater. He also said that he has found ways to make his drum recordings easier for everyone (i hope he doesn't mean triggering drums, but he didn't want to answer in specific) and improve his sound, so i guess BTFW levels of drum sound or better are to be expected of the next album.
As far as grooving, i personally feel that MM has more dynamics and groove than MP, he might play superfast some times, but he is definitely a very different drummer, he feels the rhythm in a certain (unique) way, and he is sometimes more subtle in accenting things and complimenting the other instruments. Of course crappy drum production doesn't help, so maybe this is why he sounds robotic. But listening to his natural sound during the Zildjian day event, where he played TEI and part of IT, he is definitely a groovy and very powerful player.
So i guess on the new album, first of all the drum sound needs to be improved (and all the cymbals should be audible this time, not buried) and maybe Mike will try to be more experimental. Of course in the end, it is a matter of production, so if JP rejects some of his ideas, it's not entirely Mike's fault for more generic sounding parts.