David Berning Quadrature Z or Vitus SS-101

I've been using a Vitus SS-101 for some time and it's certainly a fantastic amp. I've been wanting to try a great tube amp that's not sloppy in the bass and i've negotiated the purchase of a David Berning Qaudrature Z. I will a/b test on my system and sell the one that loses the shootout. Any thoughts on what's the better amp?
FYI, David Berning doesn’t do a lot of amp building these days but his amp designs can be purchased at Linear Tube Audio. He works closely with Mark Schneider to build these amps on a larger scale and more affordable.
this thread
at least for me
is extreme reinforcement to chase those passions NOW !!!!

RIP dude