jeff rowland 501 & 201 vs. bel canto ref1000

I am looking for anyone that has compared the three and your opinions on them.

I'm looking to step up from a bel canto s300i. Using gallo ref 3.1's

Any input will be appreciated.

I had the original Ref 1000's a few years ago- certain things were phenomenal- prodigious bass response; super low noise floor; wide bandwidth; decent texture- however, the highs were (slightly) grainy and mids not quite as 'organic' as other SS amps I have had and now own (i.e. Symphonic Line RG4 MKIII- much better liquidity), and sometimes sounded a bit 'thin' depending on the pre (impedance mismatches perhaps?). Anyways, I heard they have a 'MKII' version out now- perhaps some of these issues have been addressed- the technology holds much promise and from what I have read, all ICE amps are not created equal- perhaps the Rowlands are a step us as well- I hope this thread gains some traction...
I am thinking about the mk11s myself right now. Judging by specs the input impedance has been made much easier to drive. It was 10K/20K ohms now it's 100K/200K ohms unbal/bal.
The boards are totally changed with much higher capacitance and rfi shielding. I live in Texas and power bills are high anyway and I'd love to do without the heat. Definitely the next generation, but I think we'll see lots of advances quickly which may make technology obsolete quickly until engineers figure it out.

Did you ever try the ref1000's with a tube preamp, by any chance?

Thanks for your help man.