[edge]

Raising small out of position also makes it very unlikely that you take it down preflop. A lot of the strength in raising preflop with a wide range is that you can take it down from any position, and without that ability, you have to change your range to include a much higher percentage of premium hands.

Edit: I think raising larger in early position and smaller in late position would make more sense. Of course, you'll almost never steal the blinds with a 2.5xBB open from the button, but you'll be playing a pot in position against a wider (read: weaker) range than with a 4xBB open. When in early position, your 5xBB open charges people to play pots in position against you.

I stick to a standard open regardless of position, so this could be completely wrong, but it makes some sense to me.