used Snapfish for years now. I love them. I started using them when I was still on film. I could print out my own mailing labels, send it in and in a few days, the pics were online. Then a few days after that, the prints came back to me with the negatives.
I used them back then because they were the only one who did matte finish which I prefer. I hated glossy finish because of the fingerprints that would get on the prints.
Now that I've gone digital, I haven't used them a lot because I don't print out that many pictures, but their quality hasn't gone down in the many years I've used them. I like that they use Kodak processing for their prints (the only way I go).
I wouldn't hesitate to use them.