It strikes me as remarkable that the Kawai recording is already from some years back. To my ears you sound more grounded, musical, at home, whatever the proper wording is, on the Kawai grand. So that also led me to a (false, as it now turns out) impression of being your more recent, more developed playing.
I can understand why you would think that. The acoustic recording was done when I first learned the song and I was playing it much more regularly back then. However, older songs don't get practiced as much when new songs are added to the repertoire.
I really hadn't been playing the song much when I recorded it with the Blüthner for your thread, and I'm sure that accounts for the difference you hear.