My regular cruising group has actually switched over from preferring MTD to fixed schedule dining (we prefer the late dining option). Basically, we had been using the MTD option because we didn't like being fixed to a particular time as the activities we were wanting to do changed pretty much nightly. The last few cruises we were on though, we couldn't make any reservations before 1930 ahead of time (and I started looking 6 months out), and on the ship itself we weren't permitted to line up at the designated MTD dining room until 1900 to 1930. Not sure if that's something universal that's been going on, but as a result, we decided that there wasn't really that big of a difference timewise between doing MTD or late-seating standard dining, and as such, we'd prefer to have the same seats and the same waitstaff every night.