Lovely work Deb - isn't it great when you turn an 'problem' into a 'design opportunity'
I would (and have) backed quilts with pieced backs just like you've laid out. As one of the other posters said, you only see one side at a time! And there are some pretty nice books out there with 'reversible' quilts.
It's your quilt, you get to decide!
One of the things you'll need to be careful of if you do use this - and if you do stitch in the ditch (or other designs that follow the lines), you'll want to ensure the backing is lined up well with the front so the stitching looks like it belongs with both.
Be sure you let us know how you finish it up