I listened to the Volot for a couple of hours today and did a brief comparison to the Formula S and Powerman. Initial thoughts are that the tonality is similar between the two but the Formula S sounds a bit larger in stage depth and width.
I'm going to continue using the Volot as my main amp for a while and come back to using the Formula S and Powerman once the Volot has "burned-in". I haven't noticed big changes with burn-in before but it won't hurt to use the Volot for a while longer before comparing to the XIAudio stack.
Sound impressions of the Volot are similar to my first time around with this amp. It sounds very real, with excellent dynamics (I think perhaps a bit better in the bass department than the Formula S). Stage seems a bit small but maybe that will change with time, I think
@Fafner mentioned this in their impressions. I just need to spend more time with this amp to figure out it's sound and how it compares to my other gear. If you have any specific questions about it and the sound I can try and answer those.
I would refer to my earlier impressions if you want some more in depth thoughts about the amp for now as I still stand by what I said earlier.