Paul - you should start a separate thread of 211 vs 845. It all depends on A. The amplifier design, B. The actual 845 and 211 tube used. Of course a NOS 845 in a well built amp will sound better than a new cheapie 211 tube in a poorly built amp!
I have a lot of experience with both and overall, to my ears, generally speaking, the 211 is better. It's generally, in most applications, smoother, meatier sounding and gives more of a classic tube sound. It's one of the reasons why you see the 211 in the classic tube amps like Kondo, Air Tight and many others. Also, many new designers, like Lukasz told me, just like its sound better.
Generally speaking, I find the 845 has a harder sound. And let's not forget, the 211 is a classic tube in every sense of the word. Like most tubes, it was used in a wide variety of applications (not just audio). The 845 tube on the other hand, is a tube that was purposely built for audio. You would think that would give it a leg up, but to me, it doesn't. YMMV.