I used Shutterfly from 2006-2008, but I switched to prestophoto.com in 2009 and have printed probably 40 books with them.
I had issues with shutterfly, the lamination of my older books has starting to become loose, I'd have covers that would be off, so the bleed wouldn't be right, I'd have white edges even though it didn't show that way in the software. I'd printed probably 20 books with them. I started wtih 12x12 and then did 8x8.
I prefer their 8.5x8.5 size to shutterfly's 8x8 size, they're more affordable. You can get more layouts to an album. They have templates you can download to make sure you're in the cropping guides. I started adding a .25 border to my pages just to be sure because I was loosing some stuff in the gutters of the book.
They also have lay flat books.
For a while I added just a white border and that was fine, but I'm transitioning out of that.
Here's one of the last books I printed with their .25 inch border.
https://www.prestophoto.com/bookstor...0Leaf-Page%201
Another one I did a couple years ago with a smaller white border that cut off in the printing process.
https://www.prestophoto.com/bookstor...0Leaf-Page%201