Still too early (only had it for a couple of days, maybe a total of 4-5 hours of listening) but here are my findings on various modes:
1 - I don't like the 3D function. I think I prefer it turned off. It does expand the voice (as in coming from a wider space), but to the expense of detail and "punch". It also causes (in my opinion) the voice to be not so intimate.
2 - The bass Boost is nice, but only at the minimal setting
3 - Among the three modes (solid state, Tubes, and Tubes+) my preference is for Solid State. Something is lost on Tube and Tube +, although a bit better on the "+". Still have to experiment with it though.