Sadly I don't think I will be upgrading to TMT6. I have been with TMT since TMT2 was released in early 2008 and for the most part have been happy with TMT. I haven't had as many problems with TMT5 as others, but I did wait patiently for auto refresh and then when TMT5 was released it didn't work at all with my system and with every update through .146 I have never been able to get auto refresh rate to work and for those infrequent LPCM audio streams I have to always go in to the audio settings and manually change them. I also incurred stuttering often when streaming from my server which I always resolved by copying the movie to the local drive (PITA) and to be honest I never believed this was a TMT issue, but an issue related to how it is served up using mymovies and WHS2011 (but still to make it user friendly and convienent I need some kind of jukebox player frontend). And now if I want to update or upgrade to TMT6 I have to contend with Cinavia (I upgraded to check it out, but it was a no go on several ripped movies so I reverted back to 5.3.1.146).
So I decided to trial J. River MC18 (no cinavia) several weeks ago and WOW I was so impressed I purchased it a day after I began the test. Auto refresh rate works everytime perfectly, LPCM just works, I get MADVR as my video renderer and I don't get any sutters when streaming from my servers. It isn't for everyone since it doesn't do menus yet and no 3D, but for those that don't need or want menus and aren't playing 3D stuff you should check JRiver out.