I'm not sure what "library quality" means, but it's my understanding that all of these (and blurb and iPhoto) are using HP Indigo presses. Assuming they are operating their machines within spec, the real differences will come down to paper and binding options, customer support, and how much flexibility they offer in their workflow. One thing I noticed with blurb is that I was able to get much better color by taking full control of the process. Rather than using their software and uploading RGB files, I did my own CMYK conversions using their icc profile, did the layout in InDesign, and sent them press ready PDFs. The color was right on the money, and the printing was what I would expect from the Indigo.