Hmm I never spent much time playing real pianos. But I was noodling around on a Hammond SK1 at my local music store the other day.

I really liked the keys on that. It's hard to explain but the keys, especially the black keys, went straight DOWN instead of down at an angle. I found this to be much more ergonomic. Some chords that are genuinely uncomfortable on my Pa800 or E50 felt a lot more natural and easy to play on the Hammond.

I would also like to add that the rebound action was very "quick," i.e., easy to repeatedly strike the same note. The front of the keys were fully boxed. Sometimes this has been described as "piano style," although I don't appreciate what difference this makes.

I can't play very much without Auto-accompaniment and $1800 is too much to spend on a controller. Otherwise...