Yeh there are a few different types. I think the one i have is suppost to be generic, but my friend was saying something about them being good or something or other.
I find people on tech forums over do it on power supply's, I mean I'm not gonna run quadfire on my 430w, but my friend can run his 4850 and theres a member on this forum with Sli 8800gs or 8800gt's and he runs of his 380w antec (even though the earthwatts are really good).
Edit: X-bit labs - Roundup: 14 Power Supply Units from Thermaltake (page 18)
They give it a pretty bad review. Personally i can't complain, its been running strong for 2 years now. Also I'll point out that the price of "$45 or even more" is rubbish or was the old old price. In Aus they have them on sale for between $25-$35, so America must have cheaper/similar.