Shutterfly photo book quality?

I had a baby in April so for Christmas I wanted to make photo books for all my family members through Shutterfly. I just created a 12x12 book online and I'm a little worried. Before I go and purchase $150 worth of these, I want to get others' opinions. I have pictures on there from a variety of different things (droid x, droid razr maxx, sony dch-10, nikon d90, nikon d3100 and nikon d3500) I tried to get all the pictures from my phone to be smaller in the book so they wouldn't be too bad, but looking at the pictures from even the nikons they look a little blurry or pixelated when I preview it. Is this normal? I just don't want to pay $150 and have crappy looking pictures. I'm looking at all the pictures on my memory card and they look perfect. Is it just because of their website or something?

I can't say for stutterfly specifically, but I can tell you that online previews of such projects don't tend to display at full resolution. Few people have the bandwidth to really manage this in anything even approaching real time!
My suggestion would be to get one of the photo-books made up As soon as possible, and if you like the result order the extras.

I have ordered books from Shutterfly. Quality is ok. Not stunning, but ok for non professional use. The other answer is correct about the online viewing of the book. It is a very low res rendition of the photos and you can't judge quality by that. The finished quality will be no better or worse than what you upload. If your photos are at least 240ppi at the intended size and look ok on your computer at that size, then they will reproduce ok in the book.

Shutterfly has satisfaction guarantee, if you don't like them, I'm pretty sure you can return them. But you might want to call to confirm first.