***UPDATE***
Installs without any hitch, runs great so far but doesn't update with manual update files.
Not tested thoroughly but much improved over previous (below).
***OLD INFO***
PSP9 will "Save" (although "Save As" is touch and go). (see Tips & Tricks # 740)
Undo:
The Undo system utilized by v9 is clearly different from the one in v7 (which worked flawlessly). In v9, you will get repeated warning messages that it was unable to update the undo buffer. This will usually go away (though you may have to disable undo and then re-enable it again). You have to tinker with this. At first it looked like this would be a constant issue. But it rarely affects me. So I am very pleased. Also, from what I can gather, the undo system does work. You should save often and if you need to, get into the practice of using iterative saving (saving changes as you go). I'm not sure how much of the undo system will continue to work, but I have had no problems.
Printing:
This will hang. Don't do it. I haven't played with Print Layout or Print Preview. But it's a safe bet that there would be issues with these as well. I also think you should stay away from things like Twain functionality, though it never hurts to try something at least once.
Results:
After limited testing, I am getting a LOT of functionality out of PSP9. But because the 80/20 rule probably applies here (that 80% of the time, you'll only use 20% of the features of a program this complex), I may be using many of the functions and features that work well. So because you may use a completely different 20% of it's features, your mileage may vary.
I gave it a Silver Medal because, for the most part, it does everything I need it to do. I know that there are still some hiccups that I will discover over time but right now this is one solid app, and it is holding up well.