Hell, I always keep halves of 200mg caffeine pills around when I use my pain meds. Sometimes I just have shit to do and no motivation to do it. Pop 1/2 a pill and bah-da-bing, I'm ready to roll. When I was much younger, I was on Fiorinol for migraines and it had something like oxycodone, caffeine and something like what they used to call "blues". If it didn't help, why would they make them like that?
Personally my problem is when the end of the night comes, I have to take Ambien or 5-6 Benedryls to sleep. Sometimes the brain cuts off before the body is prone, funny but not really. I honestly think I broke my arm last month on a fall. I need to get the timing down on when to sit down somewhere. Anyway, my vote is that caffeine helps the experience.