As a non-piano-player I bought EZKeys as few months ago. Useful sampled upright with a variety of different models built in, plus all the 'look no hands' magic.
Though thinking about it a bit more, I frequently take the midi out and send it to Sonivox's EightyEight (which came free with my keyboard).
Probably less useful to you if you have a keys player on standby but still a very useful tool for fleshing out demos or even backing parts in final tracks.
Sales come along frequently...
Haha, the player on standby is myself, with an average of fifteen minutes practice per bar, plus time to glue them together. Took half a day to make a 1.5 minutes part, so not exactly Wolfgang Amadeus, no. But I had a clear idea of what I wanted so it was fun.. I decided I like it and to keep it, so tomorrow's it's on the second half, which will then hopefully suggest and interplay with a guitar instrumental. Or maybe not, we'll see
I like the physicality of the big Roland keyboard, it feels like a real piano to my extremely inexperienced hands - in the sense that you can play piano and forte!
I had a look at EZKeys but did not find how to tune it in concert pitch and the part has a lot of rubato, so the quantization of the creation tool is a pain in the rear side, as you can't disable the snap.. the pianos sounded good (but then most of them sound good to me, I realize