The Supernait is completely different animal, not really comparable to the BYOB, to be honest I like the BYOB a bit better. However the XS has more energy and drive than the BYOB and it has a very similar fluidity what I like so much in the BYOB. If I am using the Altmann Attraction DAC, I prefer the BYOB a little bit more, but in my other system with pro DACs (Mytek, Lavry) and a Promitheus NOS DAC, I prefer the XS.
By the way:
if you are looking for the perfect speaker for a BYOB, look no further. Try the Danley SH-LPM PA floor monitor

An 8 inch coax speaker inside combined with Tom Danley's tapped horn enclosure and Synergy crossover, 95 dB sensitivity, 60 to 20 kHz bandwidth and works very well not only with the BYOB, but with the XS too.
I have few pictures if you are interested in seeing the XS and the floor monitor in one system with Mana tables
