ImagePrint 10 was well worth the money for me, including practical enhancements like output sharpening. Expensive, sure, but if prints are the end game (as they are for me), then the cost is relatively small considering all the other costs sunk into camera/lens gear, printer, software, print materials (inks, papers, etc), matting/framing/display tools and materials, etc, etc. And I find that small-ish investments in the back end of the workflow often produce greater incremental value than in the front end in terms of print quality.
Ironically, one of the best aspects of IP for me is that it avoids all the messes in the Apple/Adobe/Epson chain, particularly when new iterations are introduced. That is, as long as the user doesn't make any changes him/herself without checking compatibility of important applications. I learned that the hard way after implementing a new O/S version a few years ago, only to find that it didn't support my NEC SpectraView software. That won't happen again. (BTW, I'm still running Mavericks.)
Jeff