I use 3dprinterstuff all the time, and I've recommended them to many people. I've never been disappointed.
I do know that when they first went into business, they went through several formulation issues with their supplier, and I am sure a lot of bad rep came from that.
Makerbot plastics are nice, but pound for pound, more expensive. I think for $48 you get a little over 2lbs there, not including shipping.
Ultimachine has some of the best customer service I've seen. I've tried their ABS and PLA, with no complaints. The color selection is very limited, and when they run out, it's out for a while.