It is a little better, it is newer design but has not gotten good reviews. The size of the PSU is not going to affect your bill it only pulls from the wall the same amount as your components use. That is 500 or 600 watt with the same efficiency would have the same effect on your power bill.
It's very easy to do the calculations to properly determine exactly what PSU power in watts and 12v rail current is required for your current or future PC build. No guessing is required. You can also determine what PSUs are quality PSUs as not all model from suppliers like Corsair, Antec, Rosewill, etc. are quality PSUs.