One of the car programmes, possibly Top Gear, did a really simple test a while ago. They had two groups of people & kept one awake for something like 36 hours, and kept the other group topped up with alcohol. I think the result was that the sleep-deprived group performed terribly - they were all over the road & couldn't hold speed. The drunk group were much better - fast reactions & good attention.
Personally I never drink the same day I'm flying. And wouldn't drink much the night before as it would prevent me from sleeping properly. Is it really worth the risk?