I’m currently working on an HD cut of the Director’s cut with the HDTV as a base (although while I include the new SFX shots, I mostly don’t include the altered shots to keep them in HD). The HDTV does have noticeable compression and it’s not very high detail, but it does have more grain and a much better contrast than the BD. One thing that’s interesting is that in the director’s cut they removed a lot of frames that had splice lines, but not consistently, so it’s a pain match that in the edit.
Have you ever listened to the audio commentary? Not sure if it was on the DVD commentary or on the startrek.com commentary, but it was fascinating to listen to it. They have explained that they have cut almost all scene, the guy even said that in some scene they cut like 1 or 2 frames.