I hope this isn't too far off topic...but...
What I actually find with my 605 -- which is (one of) the predecessor(s) to your 608 -- is that I cannot tell any difference whatsoever between the lossless DTS-HD Master Audio tracks and their core DTS signal brethern, off the same disc...and I have demoed at least a dozen titles already to confirm this...
When I was running my first generation Blu-ray player, a Panasonic BD10A (which is the predecessor -- or one of them -- to the Panny deck the OP is looking to get), the player didn't support Master Audio at all, so it would strip the core DTS signal from these soundtracks and send them bitstreamed to my 605. I have since replaced the Panasonic with an OPPO BDP-83 which bitstreams the full lossless Master Audio codecs to the 605, but I cannot hear ANY difference between the core DTS extraction and the full lossless extensions of these same soundtracks. Perhaps we're not supposed to hear them or maybe I am not running "premium" enough gear

but that's what I experience.
Don't even get me started on the lossy/lossless thing -- I don't think lossless is everything the studios cracked it up to be. Sure, some DVD soundtracks have improved dynamics on the subtle side on some titles, but for the most part I do not experience a night and day difference between the new lossless codecs and the legacy lossy variants i.e. Dolby Digital & DTS.