Never ever trust people with vested interests or financial stake in the outcome to advise you which way to lean. They can tell you things that are so obviously wrong that it will shock you.
Identical titles on BD and HD DVD usually should look identical. Recently MI:3 was pointed out where the BD version was technically superior to the HD DVD, but I believe that is probably an anomaly, since to most people, good digital mastering is the one that makes the most difference in the quality of the disk, with the encode being a far 2nd (unless they screwed up like they did in MI:3 on HD DVD).
There are some very bad PQ on some BD disks, and there are very bad PQ on HD DVD disks as well. Nowadays, there are a lot of good PQ on BD, as well as good PQ on HD DVD.
The fact is, when properly done, it would be very difficult to tell the same movies apart on both formats, and although BD has allows a higher bitrate to make it theoretically possible to encode higher quality video, this will only be visible to trained eyes on torture tests. Most people will be unable to tell an encode with a peak limit of 28Mbps compared to one that has a peak of 40Mbps unless they are told what frame to stop at and to advance frame by frame --- and even then, only if they have two identical TVs side by side.
Add to that the film grain issue and some people with personal preference for filtering out of grain, and that complicates everything, as it is possible now for encodes to be done where the frames are obviously filtered and must be different to the original, yet some people may prefer that look.
My preference is that grain should not be filtered, that it should look identical to the original. If somehow the 1080P digital master obtained for compression were to be of such poor quality that the grain looks unnatural, or if it was a cheap 1080P scan from a poor quality print , the studio should NOT use this as a digital master. A better master must be made available --- preferably from the DI 4K or 2K --- this is really what we should be asking the studios to concentrate on to give us the best quality disks with the best technology available.
If you look around, the boxes with blinking lights are actually meaningless, it is not the box that makes you happy --- it's what movies you can watch with it.