Stick,
I own Cary 805s and have A/B'd the 845 vs the 211. In that amp, I prefer the 211 because, tho it's sounds slightly "darker" on the high end, it strikes me as offering up a more satisfying overall tonal balance. The 845, by contrast, sounds a bit more forward and dynamic. The difference is pretty subtle to my ear, but also pretty consistently there.
I've been told that the tubes spec the same and should sound the same, but I've always noticed the delta described above. Of course, that's one set of 845s vs one set of 211s in one pair of amps, so it's hardly a statistically significant example. Therefore, take it FWIW.
Marty