I am going to upgrade my PC over Christmas, and right now I'm trying to pick out a PSU. I would like it to be fully modular, 80+ gold or better efficiency and preferably cheap. I found the Antec HCP750 Platinum and it looks awesome. It's very cheap (as far as platinum rated fully modular PSUs go), and has plenty of wattage.
However, now I'm wondering if it has too many watts. My maximum estimated wattage is 457, and the Antec PSU goes up to 750. That seems like a good thing in case I ever wanted to, say add additional video cards or more powerful video cards. Are there any downsides that I'm unaware of to having significantly more power in your PSU than your pc will actually draw? (Electricity bill, longevity of parts... etc.) Should I go for something more reasonable, like a 500-600W?