pathos
How does Old Lady & Emperor compare to the pianos in Kontakt -Berlin, Upright, Classic , Steinway?
About the same or much better?
Much better in my opinion. The Old Lady in particular has a lot of character, very dark, warm and round; you should read bitflipper's comments on her earlier in this thread particularly about the instrument itself.
One warning/piece of advice for the aged or those with arthritus--I ended up having to adjust slightly the velocity slider in Sonar for my SampleTekk pianos. This has more to do with my aging weak hands and muscle deterioration. Whereas the SampleTekk Black for Kontakt (the new one) has three velocity curves plus a velocity sensitivity dial right on the GUI, for the other/older SampleTekk pianos this is not built into the GUI itself, but velocity is easily adjusted by just moving the velocity slider on the midi input source channel in Sonar itself--but don't overdo it. I had been cheating The Old Lady by not giving her the right touch. Now that this adjustment is made, she and I are much happier partners with our tickling games (on the ivory of course). I think that the Kontakt NY Grand and Berlin, etc... have a velocity curve option right on the GUI. Having said this in my case, I find that the SampleTekk pianos to be fantastic and worth much more than they are charging for them right now on this sale.
If you have doubts I would recommend to just buy one at this discount price ($25), try it out, and you will probably come back for more. The sale lasts until July 27th; so you have time.