He's an amateur pianist who plays mostly Chinese pop music.
The immediate thing that comes up to my mind is technique, but then that sounds so boring!
I decided to answer,
"If you could play your piece as touchingly and beautifully in half the tempo, probably you can play the piece in regular tempo really well."
What I mean is that notes and even and tone are elegant even when speed halves. It's hard for me, and hard for everyone. But if you want to pursue perfection (knowing that you can't achieve it), then go ahead! It's the right way!
