Guess what? I bought yet another piano! This time it is "MyPiano" from FluffyAudio. And.... like Alicia's keys, I'm definitely not a fan of playing it live. There's something about the response that just feels wrong under the fingers, and I dislike the tone when I'm actually playing it - somehow, the high notes sound very close, whilst the low register sounds very distant >.> There is also an odd lag - as if I'd set my buffer size to 256-ish - that only shows up in certain passages. I'm already got my buffer down to 64, and tried it on Kontakt standalone as well as Konkakt inside Logic. Same thing.
Being not too happy, I booted up the Pianoteq stage demo for a comparison, and (*&£$ yeah, I loved how Pianoteq responds to my playing. However, I decided to record the midi this time, and applied it to MyPiano (as well as The Old Lady). And it sounds... pretty good! Especially after reverb has been applied and some mild limiting on the output stage. Old lady sounds good as well on this midi, just different.
Pianoteq on the other hand was more difficult to tame in the mix due to the immense dynamic range - perhaps that is why I don't really enjoy the rest of my virtual pianos - their dynamic range seemingly pales in comparison to pianoteq.
Hence, I think I've come to this conclusion that the many piano VIs I've licensed just don't play that well as a live instrument. Heck, I prefer the piano's onboard sound chip's response versus all the virtual pianos I've got, apart from Pianoteq.
Guess I'll have to get me a pianoteq stage license some time down the line for playing, and the rest of the piano VIs for sequecing, because I do love their tone :3 I played a bit of my jazz grade 2 stuff on MyPiano, again, it sucks under the fingers, but the tone is good, so I think this is a good purchase, with the caveat that I don't like it being played live :3
Edit: Tried some bach midi's off the web with all 3 vis mentioned above, sounds damned good, though arguably, I prefer the tone of both the sampled pianos. Best tool for the job I think; pianoteq for playing as a live instrument; sampled pianos for sequencing and tone/character :)
Edit 2: After tweaking the "Velocity Control" page, MyPiano becomes much more playable, though even with low buffers, it still feels laggy. Ah well.