Today I was playing(or rather plunking) on a Kawai grand. The piano sound was marvelous. I've yet to hear that sound out of any electronic keyboard I've played.
And, unfortunately, you're not going to. The upside of playing a piano is the artistic expression you can milk out of the piano and the "thickness" of sound. The downside is you'll never again want to play anything other than a real piano when you want to hear "real piano."
I've been playing arrangers for some 30 years now. And I still love them. But once you start playing a quality acoustic piano the last thing you'll want to do on an arranger is use the piano patch.
I'm still going back and forth to the music stores to try out the pianos for any future piano gigs. Played them all by now.....Casio, Yamaha, Korg, Kurzweill, Roland, Nord, even the Williams. They all sound "hollow" to me now....nothing like that warm sound you hear when the hammer hits the piano strings.
The Yamaha and Kawai grands are my favorites. Play one and everything else is suddenly like playing a toy!