I bought Pianoteq 8 and now can plug my laptop into a decent but not great Korg piano.. the results are fantastic and has essentially given new life to my digital piano:
https://www.modartt.com/pianoteq_overview
It's crazy.. instead of using pre-recorded samples, it's fully 'modelled' so the computer does a lot of the hard work to essentially create the sounds. You can manipulate room position, mic position.. all kinds of different things.
I also bought a pedal modulator so my sustain pedal has become truly continuous, vs it behaving like an on / off switch