As requested, I did a brief post about some of my experiences with Ingram for publication. Also requested was my experiences with Lulu.
I started with Lulu when first did print-on-demand. I liked the philosophy behind it, mainly the clean, easy-to-use interface, the "new" way of handling publishing, and generally the interface.
Lulu is easy to use. I like how the cover images are in terms of pixels instead of using PDF. It made it easier to get a precise image in Photoshop and Gimp since they would say X pixels for the beginning of the spine, Y pixels for the other end. Both Ingram and CreateSpace used PDFs (though CreateSpace is the hardest for making covers).
Like Ingram, there was one step for enabling Global Distribution that I missed a few time. It wasn't nearly as bad. Lulu doesn't do verification steps that I know about, so it is easier to get everything done in a single session instead of having to wait 2-3 days for Ingram to approve before doing the next step.
The paper quality of Lulu is pretty good. I found it nice and thick with a decent "crispness". The smell isn't too bad either. They have only a few size options though, instead of Ingram's 30-40. At the time I used Lulu, their "mass market" size couldn't be distributed (one reason I actually went with Ingram). If you don't mind the trade paperback size (6x9) or A5 (my preferred), you're good. If you want smaller formats, go with Ingram.
Lulu is pretty good about having lots of coupons on a semi-weekly basis. Free shipping, discounts for large purposes. Usually there is a useful one about every other month, so work around that when you plan shipping.
Unlike Ingram, Lulu doesn't have setup options. Overall, I found that Lulu didn't have nearly as many nickle-and-dime costs that Ingram nails you with. That includes updating the interior or the cover. That is nice if you go through iterations (also known as "it's perfect... no, missed something" cycle that I went through as a learning process). If you are learning how to print, Lulu isn't a bad choice.
Shipping with Lulu is the most expensive, however with the coupons, it can be just as cheap.
Reporting with Lulu is fairly good. You get reports without a problem without going through the tedium of Ingram's. However, I don't get notifications, so I have to remember to download them as part of my monthly process.
Because Lulu is set at a 30% discount with no destroy, bookstores will hesitate more. Their business models works better with 55% with destroy. This means you may have to hand-sell it to stores more because they are less likely to carry it directly off the Ingram distribution system (though Lulu books do show up in that system). This is another reason I went with Ingram.
I haven't done it with the others but one point in my past, I split my publications into two separate lines. Lulu doesn't really provide that, so I have some problems reviews/accounts that are hanging around because of that. Also, Lulu doesn't have imprints like Ingram does (which would have solved the problem).