Considering they're so cheap and all...
B1 (500B/600B/700B) or B2?
specifically talking about this:
It's ok. Nothing special. Its good for upgrading a prebuilt or building a basic PC. I would not recommend one for a gaming PC that costs more that $450.
The B2 are pretty good.
If you are looking for a cheap PSU, the 430w from Seasonic is a good choice.
They're pretty okay, if you're short on cash it's perfectly fine(you could do A LOT worse). Just don't push the thing into the ground and it'll chug right along.
A low end psu for low end builds :P
they're pretty bronze.