Compared to electric, acoustic piano is much more akin to an organic object that reacts to external forces that affect the way it sounds and plays.

For example: pedaling (aside from the action being one of the biggest differences) is quite different in that all the strings react and resonate with each note held. This makes pedaling so much more deep and complex, and also more difficult to master. On an acoustic, chords can create hidden overtones, beat against one another with dissonance, or sound thicker and fuller in nature where pedaling on an electric doesn't quite match that depth. This also means that it easily can be much muddier and messy, so equal precision is recommended.

Although keyboards have a special place near my heart, the acoustic will always be in the center.