Concerning Print on Demand and Blurb: I have been to the Photokina in the last years where all the print on demand companies display their offerings. The offers in price and quality vary immensely but have improved sharply over the last four years. That said Blurb sort of takes the middle ground - both in price and quality.
Yes, the thicker paper feels better. It is more of a haptic experience than a visual experience. The images do not look better but the book gives a more 'valuable' impression.
The thick uncoated matte paper needs special preparation of the image files - the paper used muddies blacks and details, so take that into account when preparing the files (images need to be slightly lighter than for inkjet output/details/sharpening parameters!).
Blurb in general has issues with true black and white images. There is a color shift with images appearing warm in artificial light and greenish in daylight. To soften the effect, it is a good choice to slightly warm up all B/W to a soft sepia tone. Yes, I don't like it either - but it is the best one can do.
Color images have no issues that I could see so far.
Software to prepare the books: Somewhere in between easy and truly terrible. Try the variations for yourself and you will see. It also depends on your personal preferences and how creative you want to get with your books. The more personal customizing and layout specifications you want, the worse it gets - no numerical input in layout, just some diffuse drag the mouse and locked spaces for the cover design. Best choice would be to get the Blurb Plug-In for Adobe In Design and take it from there.
Customer service (in Europe) is excellent. Mistakes on the Blub side are rare and if there is an issue it is promptly taken care of.
Well. In all, it depends on what you need your books for.