845 Tube vs KT90

Thinking about auditioning/purchasing a 845 mono block, may cost me big money, so i'd like a few ideas on what to expect from the 845 tube image.
I have a Jadis OR with KT90 and really offers me pretty much what i love in my classical music, each orch section is heard distinctly from the others, IOW the sound stage has presence. However I've heard such wonderful comments about the "king of all tubes" the 845.
I'm wondering though, will the single 845 tube deliver the same separation of fq's as well as the dynamics of the mids are separate from the highs and lows. I do not like at all the image presented by the KT88 tube, nor the 300B tube for classical. Both from my experience have presented classical/orch as a flat one dimensional sound. A total flop.
For light rock , jazz, blues these tubes seem to be best.
So what should I expect from the 845 on classical, though I realize not every 845 amp will present the same image, inner components quality also play a big role. Just looking for general characteristcs as concerns the separtion of the 3 main fq's/lows/mids/highs.