I put together three photo books with the same 75 pictures -- one directly from Aperture to Apple, one from Blurb, and one from MyPublisher.
For MyPublisher, I used their super high-gloss paper and the lay-flat pages to let them show off their top of the line.
In short, the Apple Book is the best. The colors are correct and the exposures are perfect. The layout is very customizable and easy to use.
The Blurb book would look great if it wasn't compared to the other two. The color is a bit greenish in all the photos, which shows up most in the skintones, of course. The customizable themes and pages are great; the "ornaments" on the pages are cool.
The MyPublisher book also looks great, but (1) the photos are all a bit dark and (2) the page layouts are very simplistic and hard to customize. The background colors for each page are very simplistic (i think I could have made them more subtle with a lot of work), which renders the book a little too primary-school-ish, if you know what I mean.
The prices were all very similar (50 bucks, more or less, including shipping, for a 35-page book), but I paid extra for the MyPublisher high gloss and lay-flat options (about 72 bucks total). And on your first order, MyPublisher sends you two books for the price of one. So that's cool.
All in all, I'm very impressed with the Apple book. In addition to the best photo quality of the three, it's the only one that both prints your pictures on the actual cover and adds a dust jacket with the pictures on it. They also send a cardboard "sleeve" for the book, which is a nice touch.
These pics were from 2010, so I know where I'm sending my BIG 2011 photo book -- Apple, direct from Aperture.