SPCR

It seems the price of the 550 is about $6 more than the price of the 450. Should I quibble about any efficiency difference between the two? I thought I may as well get the 550, as it would probably be a lot easier to re-sell if need be.

My system will most likely run an E2200 CPU, an HD3450 video card, and 2 hard drives, so I realize 450 is even overkill. But, silence is key above all else, and Corsair gets rave reviews.

Might there be any efficiency differences in energy consumed with such low power requirements between the 550W and 450W versions?

The 450 is built by Seasonic whereas the 550 is built by Channelwell. If you look at the respective reviews at jonnyguru.com you can see that there is significant difference in the internal components. In my personal experience, the 450 is quite a bit quieter under low to medium loads than the 550, which IMO requires a fan swap to be truly quiet.

Well, that's great. I guess that's my first SNAFU for this build.

RMA'ed and ordered the vx450.

Anyone want my vx550 before I return it? $65 + Shipping