I don't see any problems with the sound quality or mixing or whatever it's called.
It's a good remix and stays true to the original for sure.
My problem is that it just seems too slow of a pace without vocals especially at the start. The first low note just seems to hang around for too long. The original does the same, but gets away with it better somehow, probably because Todd's piano is softer I think.
Also the way it turns into a spacey fade out irks me, and it bugs me in the original too. It's like the song is shouting "hey look at me, I'm ending so here's a sound that doesn't have much to do with the rest of the song to distract you!" Though I like your spaciness better than Todd's.
In the beginning it feels like the piano is speeding up and slowing down at times and it's really weird. The first few notes have a nice tempo and then the low note slows it down oddly.
I think it'd be nice if it could sound less mechanical as well, it feels like the notes are being played by a typewriter all clacking down perfectly.
Ah! I realized now that it feels like two different pianos are playing the low notes and the high notes.
It's something I learned in choir about the piano, the more experienced you become at playing it the better you can link the notes together. Big notes are followed by a series of smaller (lighter) notes that seem to flow together. When I listen to your piano and Todd's and think about big notes they seem to happen twice as often in yours.
And with that I hope I've given you something to work with =D
Good job!