thermaltake has a bad reputation for psus in general. the thing is there are only a few actual PSU manufacturers. most companies order them, and slap their name on the side, so you get a mixed bag where some of their models are from a quality manufacturer, and some are crap.
always check for professional reviews when buying like hardwaresecrets, jonnyguru, techpowerup, etc. for instance I know they make some decent 750W ones because a guy had.one in another post and the initial reaction is "its the PSU" but you can go look up that series reviews and find its actually good. so you can't assume they are all trash and make someone waste money replacing it, but when you are buying its much better to go with a brand with consistent high...