I don't remember an extended period of time that I've been "well-rested" for nearly 4-5 years. I tend to mentally and physically crash around 5-6pm and around 2-3 pm but I typically catch 2nd and 3rd winds...

In terms of the OP... I think it depends on your sleep schedule the previous nights... If you are well caught up on sleep.. i think staying up may be the thing.. as you can power through that.. if you are regularly getting <5 hours of sleep a night, the power nap is definitely the way to go, because you've trained you body to function on less sleep. But the diff between some and none at that point are huge...