Received mine earlier this week. Great sound, very pleased so far. Very similar to my original Gilmore Lite, with four major noticeable improvements so far, in order of importance:
(1) A different, rounder, arguably more natural-sounding tone. The original Gilmore Lite had (to some ears) a kind of sharp or emphasized treble, and that is completely gone in the mk2. I think some people will appreciate this change, but it does make it somewhat difficult to compare the sound of the original GL and the mk2 in other respects. I need to do a lot more serious listening, and probably burn-in/warm-up, before I have more to say on the sound.
(2) A somewhat more powerful output stage, though there wasn't really any problem with the original to begin with. For reference, comfortable listening had the volume pot at around 10:00 with my HD600 on the mk2 instead of around 11:30 on the original GL. I think on my LCD-2 I maybe turned it up to 1:00 at the most. So there's plenty of headroom on my most-used phones.
(3) A much nicer, super-smooth volume pot and knob with perfect channel matching throughout its range. In contrast, the original GL had a little grit and some noticeable unevenness at very low volume levels.
(4) A nicer feeling and larger case with nice sticky-rubber feet that is much less apt to slide across your desk. Weight is approximately the same. Linear power supply is the same size and specs.
I will post some comparison pictures later, and possibly more sound impressions if I am satisfied that I've come to any conclusions.