Got mine today and was comparing it to the saved DVR recordings of the HD broadcast on that HD channel. And for the most part I like it better, with blacks looking more solid, but I am curious why some scenes do have a change in color palette. I mean it could easily be something like correcting a shot that didn't follow the DP notes, or it could be a mistake. Simply put without more detail its impossible to know.
With ENT as the only show shot and delivered at a higher quality of modern Trek, teh change isn't as dramatic as the utterly awful DVD to Bluray of TNG (those DVDs were terrible), not to mention actually saved recordings of an HD broadcast even if 720p, are going to make for a much smaller improvement.
But improvement it is. Considering visually ENT is easily my favorite Trek series (from set design, to costumes, to location work to the various ways the DP filmed the show), I am quite happy.