Can anyone comment on which does a better job with photo image quality: lulu, cafepress, imagestation, whatever?

I've found that the print-on-demand industry is extremely variable. Some of the stuff I've gotten (coloritprinting.com) has looked great and other stuff has looked like complete crap (cafepress). It appears that the image resolution is irrelevant and that some of the printers ignore embedded color management profiles, etc. It drives me nuts. The cost of the service doesn't seem to correlate to its quality, either.

Has anyone had any really positive experiences with print-on-demand houses that they care to share??

mjr.