Hi Mark, good questions.
1) I moved to ImagePrint primarily for B&W workflow. To my eyes the tint that comes out of IP matches what I expect, whether I want neutral or some specific tone. As I mentioned in the other thread, you get to see the effects on the paper as you experiment with tints. Using the Epson Advanced B&W you just have to experiment and print - there is no print preview. Using LR, you can soft proof but it is a bit clunky for experimenting with tones. But there were four other benefits I found:
First, when trying new papers it is much easier to get an excellent print right out of the gate because the profiles are quite good for all media they cover. I can make a better one, but that takes time I don't want to invest while experimenting with paper I may never end up using.
Second, when printing 20+ images for a job, it saves me time and I have less waste from human error. That's specific to me, but we're talking about my choice here (more on that later).
A third thing that I am just finding out literally as we speak is that I can see the effects of output sharpening like I can in PS, but not like LR. LR has sharpening, but it is added on the fly. I don't use PS much so IP is better than LR in that regard (again - my context). In IP you get to see the output sharpening with the paper profile applied in a very nice preview with comparison before/after. You still have to interpret how that will look on paper, but I am starting to see real value in using IP for that step.
Fourth, As Martin so eloquently pointed out here in
Post 25, I haven't had the printing path break since I started using IP. In fact, to do the test I did this morning on resizing in IP, I had to uninstall, delete and reload my Epson driver to print through LR! It would start printing but then in the middle of the print just lose communication and spit out the paper. Arggghhh! Not to mention the recent broken color issue with Adobe. I just went right on printing through that one.
2) I think for the beginning printer, the above benefits are marginal at best. In some cases would never be noticed. IP is expensive, and just like my other equipment examples above, benefits that may or may not be valuable. I lumped them all together in my response because I think it takes time to see and know what matters to individuals and what doesn't, whether that is an expensive lens, specific camera format or IP. If someone off the bat dives into IP, I don't see how they would really know what or where the value was.
3) I do see a value for B&W prints because the tone is so accurate and you get a dead-on preview of that. In color, I don't think the quality is any different. Although I do still get the four benefits I listed above. But those are very specific to me and more workflow related than quality.
But your question used the words "significant quality differences." That's like my word "compelling." Those words are in the eye of the user. In general, I still would say "no." These things are neither significant nor compelling to the general photographer new to printing. But when you are printing several images for an impatient client, and you have a day job like me that requires lots of travel and has nothing to do with photography, then they tend to become significant.
I can't imagine them being significant when starting out. They certainly were not for me several years ago, but they are now.
Dave