One thing I'm noticing from watching lots of Cube drafts is that red burn is pretty much a benchmark deck for the format.
With a pool filled with so many "power cards" the temptation is always going to be to pack your deck full of flashy plays at the top end of the curve. But just because this is Cube, it doesn't mean that good deckbuilding can go out of the window! The red deck takes advantage of quality burn and efficient cheap creatures to win the game before clunkier decks have even managed to deploy more than a couple of their 5++ casting cost threats.
Cube is an interesting one, because it always seems to me that there are ready-made decks just sitting there in the pool waiting for someone to draft them. If no one else drafts red aggro, and you get every card you need for the archetype, you are going to do very well indeed. On the other hand, you are going to do much less well if you're competing for these resources with several other players. I guess this is the story behind all Magic drafting really, but it's more obvious in Cube because you know what decks are in there for the making. As such, watching for archetypes being passed to you, and trying not to hand them to the player on your left on a plate, is extra important.
I guess to cut a long answer short, in ordinary drafting you would slam a power rare first pick every time and be glad for it. In Cube, more of the cards are good or great, so it's less necessary to jump on bombs. Having a good deck archetype will serve you a lot better than a random pile of overpowered (in isolation) cards...