Distant and roomy. Pretty bright room too. Is it me or is it right-hand heavy? Since it is really roomy sounding, I would put a pillow behind the mic to protect the rear node from getting reflections as a precautionary step.
You didn't have to take my suggestion
I was just asking since upright pianos are about 5' wide, if your fav spot was 6-8 feet away is because hyper-cardioid mics have a centered pickup pattern of 80-90º. So, if you pulled the mic back 6-8 feet, you would capture the entire instrument in balance (theoretically) depending on the microphone and preamp's response.
It's a starting point I use for a barometer.
Another approach, which may change the dynamics of your playing, is to play to the room. The room is your audience. I know this may sound weird, but ask the room in your head (not out loud for god's sake) how it wants you to play and play "feeling" that. If you can get into it, you join the room with your piano. You should feel it too, the room's sweet spot with the dynamics of your playing and still be expressive in the performance.
For instance, here, I have a lot of gobos, wooden accordion walls, plate glass, ceramic tile boards and other things more esoteric to affect the room's response to whatever is playing in it. The room sings with trumpets when the tile boards are down. Acoustics like an accordion wall set at certain angles for an open roomy sound or quarantined with strategically placed sound absorbers, poly-diffusers and glass plate for a cool sounding early reflection sound.
Every room has a sound that can be exploited. And to exploit it comes down to what you have on hand to do so. If you have no materials, you do have the dynamics of the playing or where the instrument sits in the room and these relationships with where the mic is sitting.
Listen, I am not the end-all be-all super hero recording dude. I learn stuff all the time and a large part of that comes from experimenting and doing crazy sheit (sober!) almost daily. I read about the placement over and behind the head in the thread and that's a good idea
Split is a really knowledgable person and a goof too, so watch what he says closely.
If I were you, I would work on a straight-line plain with your mic. Keep it at a set height and move it forward and back on a single line. Make big distance changes and note the sonic differences (as many as you can) then refine to smaller ones till you find the sweet spot. The big moves will show your ear major differences and this will increase the sensitivity of your ears to hear smaller differences.
Yup, that was a lot! Oh, and play to the room too