I've had the Kawai ES920 for a few months now and it's been fantastic both for home use and gigs. The Responsive Hammer III action is excellent—it mimics acoustic piano touch very closely, which is great for expressivity and dynamics. The key surfaces acquire a nice, slightly textured feel that prevents slipping during longer practice sessions or performances.
Sound-wise, the Harmonic Imaging technology provides rich and detailed piano sounds. It has various settings to tweak the reverberation and other aspects, making it quite versatile for different styles of music. Overall, its sound quality competes well with other digital pianos in its price range like some models from Yamaha's P-series or Roland’s FP series.
For portability, it strikes a good balance between build quality and weight; It's solid yet light enough to transport easily to gigs or rehearsals without too much hassle. Plus, it has a sleek design which looks professional on stage.
In terms of connectivity, the ES920 includes MIDI and Bluetooth capabilities, making it convenient to connect with recording software or external amplifiers/speakers without needing a bunch of cables. This has been incredibly helpful during live performances where quick setup is crucial.
Overall, I think you'd be quite pleased with the ES920 if you're looking for something reliable for both practice and live performance situations.