Some of their content isn't bad but much of it IMO is real crap. I've been going through it to use myself and blurry with scan lines going through the images is going to get you declined which is what I found a lot of it was.
If you can find some that doesn't look like video screen shots and I haven't already seen it a bunch of times already I'll list it.
I did build a few sites out of it but I spent way too much time in Photoshop cleaning it up and this was only after going through it by hand to try to find some that was at least half decent.