I have had the Esoteric DV-50 (which I kept and the upgraded to the 's' status) and the Linn Unidisc 2.1 in my system (which at the time had the Linn Kisto pre/pro and fully active AV 51 system)
I love the Linn sound, or I wouldn't have all their speakers and amps, but the Esoteric was more accurate, particularly on bass. The upper end was slightly more liquid on the Linn, but the attack of the notes was lacking, and the bass was weak at best. NOW as for video, the Unidisc was more life like than the DV-50 (hadn't been upgraded yet, so I can't compare the 2.1 vs DV-50s) and definitely did reds better. In fact I would say color saturation was generally better on the Linn.
Ultimately the wife and I decided to keep the DV-50, and I do not regret it. MC Audio is a novelty in my mind, but still a great party trick, and once in a while, on the few disks that are recorded well in this format, a true treat.
I can tell you that the upgrade to the 's' status really did make a significant improvement in the video. I can not tell you how much is just from keeping the video in the digital domain (I use a Samsung DLP RPTV) over the better video board but there is a three dimensionality to images from the DV-50s via DVI out that is really impressive.
I would love to A-B the Linn 1.1, but don't want to pay that price for it.. I heard the Bel Canto Univ (I beleive the PL-1A) but it was in a system I didn't like so I won't coment on it (well, I will say it was at a store I HATE... seems the owner makes his own speakers, and voices every stereo to sound like his speakers, which to me are raspy as hell and intolerable but...).
FWIW I have had the DV-50s for a couple years, and still love it. the build quality is amazing, sound and picture are great.... I would love to have the EMM CDSD and DAC 6e, but let's face it, I bought a kitchen this year instead....