I am under the impression that a player with all the major encoding abilities is the only way to go.(DTS-HD,Dolby True-HD, Dolby digitl DTS,DTS HD Master Audio).
That's the way to go, the Denon 3808 will decode all the HD sound formats, many of the newer Blu-ray titles are in DTS HD Master. Imo it would be a waste to purchase a player that doesn't support all the HD sound formats.
I've never been all that sold on upconversion, some players do a better job than others and I've had quite a few, but to me the difference hasn't been earth shattering. Most HD movies are in a league by themselves and I find myself somewhat disapointed when I have to settle for SD movie.
