My first reaction is: I hardly ever find it!
A more considered reaction: the main thing I look for is some kind of obsessiveness. I’m especially attracted to pieces that are difficult, relentless, with fistfuls of notes, that keep me up nights figuring out how to play them. That kind of involvement HAS to transmit to the audience. But the obsession could be an inner one—sparse or abstract—with over-abundant generosity to an idea. Also, I’m biased toward pieces that “sound modern,” as in post-jazz/rock/hip-hop/commercial/noise/ambient… and ones that make use of the most luscious sonic properties of the piano.
Someone I admire recently asked me what I wanted an imagined piece to do to/for the audience. I said: “Get them up on their feet and send them to a higher plane.” It could do one or the other. Or both.