I can see this being a worthy purchase in only two situations. First, you need to gang multiple images together into a single print job VERY often or have a commercial print operation and print large, multiprint jobs on roll paper. Secondly, you want to have the BEST, STATE OF THE ART equipment, no matter how much it costs. In other words for you, price is no object.
I have a 17" Epson P800. Today you can buy a new one in the US for $900. I own and can print just fine from Photoshop. I own and do print even more easily from Lightroom. I'm usually happy with current OEM downloaded profiles and have purchased only a couple custom profiles. To purchase Imageprint for this printer would cost about $920. That is more expensive than the printer. It is more than what I paid for Photoshop and Lightroom combined! And the most recent Imageprint upgrade, from ver. 9 to ver. 10 cost $313. Oh, and by the way, I can put together a capable Windows based computer for all this to run on for about the price of Imageprint alone. It seems to me that this software is hugely overpriced in terms of value added and in comparison to the tools that surround it in a digital printing environment.
Regarding quality of output....if a skilled printer printed an image to their "best ability" from, say Lightroom, and then from Imageprint, and then showed ONE of them to you, would you reliably be able to tell which software printed the image? I doubt it. And I'm willing to bet that the public couldn't tell the difference if they saw them side by side.
Given that I have to factor value into all of my purchases, for me, this software is out of the question.
Brad