Sanders Sound preamp vs. Innersound?

I just recently picked up a Sanders Magtech amp to drive my new Maggie 1.7s and I am now searching for a preamp to join the party.
I was originally thinking I wanted to go with a tubed pre:
Modwright, SWL 9.0 sig., or new LS100.
Cary SPL-98
ARC, LS17 or LS25.

I just noticed 2 ads for a couple of Innersound preamps here on AGon that look very attractive.
The Innersound pre would be the perfect (solid state) match but I am guessing it would be much more of a neutral sounding pre, than any of the tubes units I am considering?

I think from neutral to warmer, these would ranked as:
1: Innersound.
2: ARC.
3: Modwright.
4: Cary.

Does anybody have any experience with the sound of any of these brands and if so, how would you compare the Innersound / Sanders to them?

How does the Innersound compare to Roger's current Sanders preamplifier, I know they look pretty much the same but how much has he done to improve it?