In the above case it was actually all real-time. I used pianoteq and the ASIO drivers which at least seemed to have no noticeable latency (admittedly my first time using pianoteq.) I admit you may get different results with different software and hardware configs.
Also you will see on the pianoteq website youtube videos of people using a similar config with no noticeable latency playing in real time. Not that I am trying to promote pianoteq!
I would say though there was no post editing in my recording above. Just a different piano sound then usual. I realize this is a bit of a touchy topic… Just an amateur piano player trying to get a nice recording
Sometimes too I wonder at the clean and precise sound of my electric piano ; but then I get to play on a good old heavy Steinway, and the feel of the ivories, the hugeness of the sound just dwarf the eletric piano for all its merits.
Regarding VST, I don't get whether you change the sound real time or post-play : when using VST in real time, I have quite an horrible latency (250-500 ms) which make it unplayable. And then unless you just want to make a cute recording, that makes VST useless to me ; one of the reason why I hate MIDI is because it seems that it NEVER exactly reproduces what you did. A simple electric piano with a line-in recording device, or an accoustic with nice recording equipement is much more faithful to the performance.
Also, changing the sound after you played is quite a huge edit to make I think ; the dynamics you used, some legato and rubato, it will vary greatly depending on the instrument you play. Even on my electric piano, varying reverberation will completly change my playing, as will changing the voice. For instance, I like to emphasize deeper bass lines, and I hate high and bright chime-like notes, so depending on the instrument voice I will not play the same. Those edits, I'd say, make your final result more akin to eletronic music than classical one.
In the end it merely depends on what you intend to share I guess ; a perfect studio-like performance, or your personnal performance (a question which is not unlike the ones on faithfulness to score and composer intention versus performer individuality and choices).