dvd-a
I think some people don't like them because its hard to get them to sound right. I use an oppo 971 now which only supports DVD-As, but even with it (as my older pioneer which supports both), I can never seem to get enough bass. In my H/K menu, I +10db the sub specifically for DVD-A, and they still seem to be lacking in bass compared to 2-channel tracks.
I hear some of the newer HD-DVDs supporting the newer HD sound formats (when using the analog outputs) are having the same bass management issues.
Sierra-1 - Mains+Center
Surrounds - HTM200SEs (x4 in back, and x2 Atmos)
Sub - SVS PB-2000
Receiver - Onkyo TX-RZ1100
Oppo Darbee Edition Blue Ray
Sony 4K blu ray player