I just got my Lyr+ today, upgrading from a Valhalla 2.. and even without burn-in I can hear an immediate benefit! Granted my Valhalla 2 was starting to get old (7 years) and perhaps the tubes were a little bit over their best days, but the difference is huge and I can hear details in songs I know extremely well that I have not heard before.
Loving it so far, and the Solid State stage is very very nice. It's actually one of the reasons I decided to buy the Lyr+ because replacement tubes are starting to be a bit harder to find (at least in Europe). I did get it with tube though and using that most of the time.
I do have a bit of a problem with the volume control though, but Im going to use it for a few days before contacting Schiit. I'm using high-gain with HD800's, and it stays very quiet up until like 10 o'clock. Then quiet from 10 to 2 (even dips down in volume at one spot) and then just one millimeter of movement around 2 o'clock it jumps massively in volume. It's a bit annoying because anything before that jump is too quiet for me, and after is too loud.
When it jumps you can hear multiple relays going off, instead of the normal single tick.
Getting my Bifrost 2/64 in a few days (currently rocking an old Bifrost (1) multibit Gen2 USB), so its quite the upgrade for me these days