Dream Theater is my third favorite Dream Theater album, behind The Astonishing and Awake. It has ny favorite DT epic in Illumination Theory, which for me is the most meticulously composed DT piece in terms of structure. Outside the epic, I love how each song is some sort of a short intro to a newbie of what DT songs are about (a rocking metal intro, a Rush-like rocker, an instrumental, an anthemic piece, a prog METAL song, a PROG metal song, a ballad).
If we are talking about the mix, not their best sounding album but it's not really bad. It is more of the mix works really well with the more heavy songs (TEI, BTV, EM) but not with songs like AFTR and TLG. That said:
Should be higher in the mix - keys, cymbals
Should be lower in the mix - the guitar
Just right - the bass. At first I didn't like it because it does not have that depth, but I learned to love it because it has a unique character. I also love the toms and the bass drum.
About the snare, I think BTFW has shown us how much better it could have been. Even Mangini had his misgivings, but team player that he is, he worked with the team vision. The silver lining really is that he developed a new technique because of the snare (that is, putting much of what could have been the ghost notes on the rides and hi-hats).