Interesting thread.
I have made only one attempt at vatting. It wasn't really to see if I could make a nice blend but to confirm a theory. I had a bottle of Maker's Mark Red, my second, and found I didn't really like it. I didn't dislike it either, it just didn't do it for me. Then I read that Maker's Mark is a wheatie and I wondered if I was missing the rye. I mixed a little Wild Turkey Rye with a larger slosh of Maker's Mark and tasted it. It wasn't better that Maker's by itself really, but it did confirm my hunch that what I was missing was the rye.