While I no longer own the Stratus, I still follow this thread because I loved the Stratus so much. In fact, my time with the Stratus inspired me to have a custom 2A3 amp built to drive my speaker setup.
I started my infatuation with SET amps 5-6 years ago with an inexpensive 300B amp built in China. As much as I like the sound of 2A3's, I somewhat miss the lusher mids of a 300B. So on a whim, I purchased a pair of the Sophia Electric Carbon Princess 300b 2.5v tubes for my 2A3 amp, and even though the tubes aren't completely burned in yet, I have to say I am really really liking their sound! As a bonus, they seem to be even quieter than my various 2A3s (even though the 2A3s are very quiet in my amp).
At any rate, just thought I'd share my experience and see if anyone else has tried the 300B 2.5 tubes?