DID IT WORK?: Yup.
THE RESULTS: To really see if this hack was worth it, I baked a second pie using this recipe that's very similar to the Cooks Illustrated one, except for the fact that it doesn't use vodka.
Prep-wise, the vodka dough definitely didn't break as easily as the test-pie. But it was also much stickier because of the moisture from the vodka. It was kind of a mess to handle, TBH, and I probably wouldn't pick this method if I were making a lattice.
Once baked, the vodka crust was definitely flakier and crumblier that the test pie, while still holding together well. I had a few people try it and most people preferred the vodka crust because of its flakiness. So, does it make a difference? Yes, definitely. Is it worth the effort? If you really love super-flaky pie crusts, probably. Otherwise, I wouldn't go out of my way to try it.