EQ is an extremely relative thing based upon performance, notes played, and the importance of the piano in the piece. EQ should be the last thing you attempt to use. Although just in case, here are some general frequencies to keep in mind:
2000 kHz is the loudest frequency to the human ear.
8000 kHz will make the sound feel like it is sitting above your head.
250 Hz is where alot of warmth and depth can be found. Also one of the easiest areas to muddy up an entire song.
I agree with Rozo, try lower velocity settings on average. All in all the most important part is the performance bar none. Put a reverb on a send bus and make sure it has a wide stereo field.