I enjoyed listening to the 5.1s when they came out, and like many here found that I noticed things that had previously been not so apparent. However I recently started listening to the Lamb very VERY closely (as I was learning the bass parts). Initially I worked solely from the new stereo remix (as it was convenient). After many weeks I turned to the original mix (first the DE version and then the original UK CD version) and, guess what? I noticed lots of things I'd not spotted listening to the remix.

Generally I'd say that whenever you hear a different mix, different instruments and parts become more apparent and to some, this is a refreshing change (to others it irritates). Having listened closely now to several different versions, I'd say it's impossible to beat the original CD... but I haven't listened closely to the vinyl... yet.

One final comment - and I think I've said this before somewhere else: try sitting in different parts of your listening room... you will also probably find that different parts become more apparent...