I don't pay too much attention to the power rating, so I can't really answer that with authority. If a guy has power that is a plus but I don't look for it. I look for(in this order):
Batting Eye
--most important rating to me. They result in high OBP, reducing the amount of outs they generate, and also run the pitchers pitch count up, getting to the pen
Splits
--Everyone looks at splits, you can't ignore them
Contact
--Less strikeouts, make the defense work
Speed
---coupled with contact, this can make a ordinary looking hitter much better
Switch hitting
--Magnifies every other hitting rating more than most people think
Power
--If they have it, its a bonus
Many, many players produce better offensive numbers with lower ratings simply because they are switch hitters.