I didn't plunge for the big box, but I purchased the DVD/CD sets for Pawn Hearts and Still Life. I was a huge fan back in the day, I had all of their LPS, Peter Hammill's solo LPs, The Long Hello; also saw them in concert at The Beacon in NYC. That being said, I haven't listened to them much since the early 1980's!
The opening to Lemmings is spectacular! The introduction of the instruments as they spread across the room is exhilarating and is a great surround mix to use when demonstrating to visitors. There are so many sections of music with different instrumentation and the placement of the vocals, instruments, and other effects occurring here and there are respectfully assigned a place in the mix. It is very involving.
I've listened to both the 'AC3' and DTS versions. Since I don't have a room designed with surround in mind (High ceilings, in-wall speakers, glass doors, etc.), I couldn't really discern much of a difference, not was I listening for one. Both were a very comfortable listening session. Incredible clarity on this, even on the 'whirlwind' sections, and it could very well have been a muddy mess. Hammill has a varied vocal approach, but his quick changes from smooth vocals to high screeches and yelps don't sound harsh as all.
10 for the mix, 10 for fidelity, and since this is probably the proggiest of all of the prog albums that I've heard, it gets 10 for that as well.