I've been following this thread. For the amplifiers you guys are considering, you have reached a price vs performance plateau. To get a better amp, you are going to have to spend a bit more money, or sling solder and build a kit.
I'm familiar with most of the Decware line. (When I went to Zenfest regularly, I was a Chicagoan.) I have two favorites there. I really like the basic SE84C series. Two excellent WPC. But if I were looking for a VERY flexible amp, one that you can tube roll to any sound you want, you should consider spending a bit more. Consider the Mini Torii. It's four WPC. It's regulated. There are a lot of tubes available. I doubt it will fail for the next twenty years, because it's well made and not stressfully run. Price is $1800. Definitely several steps better than a lot of amps.
If you can solder, build a Transcendent Sound amp. Any of them. They are OTL, very reliable, and about the very best tube amps at any price.
Finally, I have to mention Music Reference. The smaller amps by Roger Modjeski are world class. I can't afford them, but I sure wish I could.
Edit: Lin, opnly bafld, can you add to this?