First, Artscow can only do 39 page books, max. That's a real downfall for them. I have printed 8 books through Artscow and 1 through Shutterfly. My only issues with Artscow has been that occasionally I forget to shut off the page numbers on 1 or 2 pages and in the one book that I made for a friend a couple of the faces were really red, but it seems like that only happened on the people who were really red to begin with, drunk and using a cheap camera (wedding dance photos).
As far as customer service, you have to remember they are in Hong Kong so English is not a first language and the time change is really big. I usually only spent $10-$15 a book including shipping. I think thats worth it. Shutterfly is a lot more money. I don't think I have the patience to figure out Vivivo's amazingly confusing software, so I won't be trying that one. I currently have 2 more photobooks coming from Artscow. The more I buy from them, the more free/discount coupons I get. I have loved a lot of the other products I have gotten from them, too, playing cards, puzzles, dog tags, lots of cool things. I am going to be ordering a door mat and a canvas this week cause I got discount coupons for them, too. HTH!