Tube amp $2-3K used

That's interesting observation Chris made.

I had VT-100 Mk 1 & 3 in the past, a friend let me borrowed his Mk 2 for a week. I have also had Sonic Frontiers Power 2, 3, 2SE and currently own the 2SE in addition to BAT VK-75SE among others. Side by side with BAT VK-75SE, VT-100 Mk 3 sounded rough, lack delicacy, slow, congested, etc. I could not believe my ears, neither can 3 other of my friends. Bass was not any better, it was such a disappointment I sold mine after a couple week.

However, SF Power 2SE (or even the plain Power 2) comes close to BAT! Bass weight is significantly better than BAT, but BAT is faster in bass, or faster overall. Top end extension, delicacy, air, refinement are all top notch like BAT, but BAT is still a touch better and expected given the higher price and lower output. I also owned BAT VK-150 (not SE) in the past, SF Power 2 definitely sounds better than VK-150 overall.

This is heard in the same system that includes SF Line 3SE and Sonus Faber Amati Homage, no other variable changed.

And like what Chris pointed out, SF Power series allow you to bias individual tube from top like a true reference grade tube amp. Only in ARC Reference series do they allow you to bias each tube. Reason is manufacture cost and VT series single resistor bias scheme is a very compromised design. For SF Power series, you only need to check bias once every few months, very little work involved.

Greenman, I am using the AI3A preamp. Don't really want to get into the balanced thing. Aren't OTL amps prone to stability problems?

Trelja, I am in the NJAS. Know Russ and Fr. Richard very well. Needed to expand my net on amp choices to the internet audiogon crowd.

Semi, the only thing about SF amps is they are no longer made and what happens if repairs are needed?

I am extremely happy with Antique Sound Lab hurricane & ASL 1009-845. I have the 1009 driving Avalon Diamond and the Hurricane driving Cremona Auditors. They are reliable, easy to bias and do a great job. IMHO, they better CJ 60SE, BAT VK60, Cary V12. I have not heard Rogue 150. ARC is a pain because everytime a tube fails, it blows a resistor.

SF is out of business for years, but Parts Connexion which is run by Chris Johnson, former SF founder, will continue to service all SF products. If you don't feel like shipping it all the way there, you can order schematic/parts and have your local technician work on it.

Mine Line 3SE developed the famous volumne pot problem. I ordered the parts, got instruction from them, replaced it myself in 2 hours. You can pay someone to fix it for less hour as well.

The Atma-Sphere amps, at least those made in the past decade, are extremely stable, you can even remove output tubes while they are playing (not that I recommend this). The two caveats in your situation are that although they can be run single-ended they are really designed to be operated in the context of a fully balanced system and that they don't especially like low impedance loads (the S-30 particularly).
SF amps can be serviced and/or upgraded by the Parts ConneXion which is run by ex-SF staff.