Elizabeth, only quilting through the top and the batting means you don't have to worry about what the back looks like at that stage at all. I do agree with you that when I added my backing, right at the end, my stitches on the back aren't great, they are more like pin pricks rather than the same as on the front, but at least it meant that the stitches on the front are the same size as on the blocks themselves.
If the quilt police care more about what the back looks like than the front, then that is their problem. My daughter wants me to put my Jane in a show this year, and I think that would be their biggest critisism (though they might not like the front either, or the 'unconventional' way it has been quilted).
I have never entered a show before but I might just gather up my courage, just to see what the judges really think.