Difference between SE and balanced outs does exist, but is not huge and varies by amplifier. Some amps like true balanced inputs more than others. So lots of variables. I hear more fine microdetail and imaging is more precise.
The comparison with M51 by others is accurate. M51 has more finesse with the softer sounds. Gungnir tends to drop or render the softer sounders louder. Gungnir stage is also more compact. I found these much alleviated by Wyrd. Also I do not like Gungnir HD800 combination, but that could be that I don't really care for HD800 any in combination. Gungnir slams hard with strong attacks. In combination with the HD800's 6k peak, not a good thing. Too aggressive - sort of glare and hard sound. I like the Gungnir for its vocal rendering and smooth non-grainy high-end. The M51's high-end is grainier, but is rendered with a silky quality which isn't too bothersome unlike many other delta-sigma DACs. The Gungir is a little behind in terms of resolving capability compared to other DACs in its price range.
Gungnir should be left on at all times. The sound is less aggressive - warmer/more laid-back if left on for a long period of time.
