Anyone with W4S amps and preamp

I would like to hear from anyone who uses or has heard the W4S amps and preamp together preferably with balanced connects in respect to other gear they may have owned. I am also interested in input from anyone who has used switching amps with other peamps with good results. I am using a Bel Canto S300ui while my tube amp is in for repair and it sounds surprisingly good. I am considering moving up the chain to mono's for greater resolution and dynamics. Thanks for the replies so far.

Bel Canto gear sounds wonderful, esp the latest models. I love my REF 1000 mk2 (now M) paired with a Pass Labs XP10 pre. Wonderful combination for warm, open, wide soundstage, excellent detail, dynamics and PRAT, very deep tuneful bass. I hear very good things about the REF 500M too. I can't comment about W4S gear. Tell us about your other components...

I'm using a pair of Wyred 4 Sound SX-1000 monoblocks along with a Dodd Audio Battery tube preamp. The music sounds wonderful. I have also used a Plinius M-16 preamp with the SX-1000 monoblocks that also sounded wonderful.
I hope this helps?

I am using the W4S STP-SE Preamp with the W4S-ST-500 Power amp with Shunyata Altair XLR'S.These are powering vintage JBL 150A speakers (500$ for these in mint shape) and this combo sounds like way much more money.The source is a Sony 9100es -Modwright Mods- cd player for my den system.Also powers and supplies audio for Plasma tv.
The W4S amps have a warm,expansive sound and are capable of powerful bass,yet insightful detail.Speaker and room dependent,if you want power and volume these are great.
Best case scenario on the class "D" amps-buy a Spectron and a tube preamp.Long break in on these class D amps but they are worth the wait.Any help to you?

Thanks so much guys. This is exactly what I was hoping for. It has been a very long time since tubes have not been in the signal path of my stereo and I am twitchy. Unfortunately no way to audition similar setups within a 500 mile radius that I am aware of.