The VP 450 is slightly cheaper and comes with a power cord and is black, which I like, if I'm not mistaken, (I would have to buy one for a few dollars if I go with the Antec 380). My main concern here is the noise, I know I would be happy with the 380's noise level, would the VP 450 be as quiet?
It's my personal opinion, but I'd say that "EarthWatts" would be a much better option in this particular case.
It's slightly less powerful than VP-450, but it's of a higher quality, has better power provide (You just can't ignore the 80+ Bronze efficiency) and has Active PFC (which is a definite plus).
In this particular case it's the "spend more - get overall better product" thing, you'd better not ignore it.
Sound-wise...they're about the same ("EarthWatts" is 29~30dBa at 100% load, while VP-450 is 30~31dBa at 100% load).
I highly recommend choosing "EarthWatts" option, it would be a much better buy.
The EarthWatts is more energy efficient. I don't know if either of them is quieter than the other, nut if one is, it'd probably be the EarthWatts. If you don't want to spend a few more dollars on the EarthWatts and on the cable, then you could go with the other model and you'd probably be just as happy with it too. I don't think that there'l be a significant ifference in power consumption nor noise. This machine doesn't use enough power to make a significant power consumption difference between the two and they are low-power PSUs with seemingly similar cooling, so they're probably similar in noise generation. The EarthWatts is an arguably higher quality PSU, but it probably doesn't matter for you which way you go. If you don't mind spending the extra, then the EarthWatts is the way to go. If you do mind it, then the other one is the way to go.