To be honest, I hate them and I really hate pictage. I know people that have had success with using them. I just feel they take away from the experience with our business. Not only that, but their pricing sucks.
But, like I said, I know a few people that have a huge success with them. I think if you are going to use a service like them, then you need to buy in to the whole system.
I just used them for an album and their turn around was amazingly quick. I uploaded on a Thursday and had it in the client's hands by the following Friday and that included me priority mailing it to them. It looked great, a little higher priced, but I had heard about and needed speed.
print prices are quite expensive compared to black river imaging or whcc. albums seem very nice, and software is easy to use. I've had great luck with the brilliance album.