I am using Sennheiser 800 headphones, not the new version "S" the original's. I just changed out the Ken-Rad VT-231's for Sylvania VT-231's and the difference is palpable. The K-R's had slightly better bass, but a little darker, the Sylvania's the highs are very good indeed. Midrange is full and present in the right amount, I prefer these over the K-R's now. The 6SN7's I have had and used for awhile so they are totally burned in. The CF-Thomson's 6080 sound very good for a pair of tubes that were inexpensive. Have just scratched the surface, of tube rolling, so will take it nice and slow. As far as doing a head to head with the Ember, there is no point. I reached as far as I could with the ember with dual 6L5G's, and it is nice, but this amp new out of the box is obviously better in every way.
It is really exciting to read about your introduction to Elise. Thank you so much for sharing it with us.
Your experience with the amp fresh out of the box and the experience of @WB2016 have inspired me to go back and listen to the original tubes.