Been with PDR since 7. 7 wasn't good that good for me. Needed 7ultra to do things I needed. It really comes down to what kind of files you're playing with.
9 does the job perhaps to what you're doing currently. Just to snap the edge plus few extra options could do it for your last production. 3D for sure, other stuff is painted on the sky like your last production; Extra something.
I don't know but I feel I need to have it (so sue me). Painter wants to have the latest brushes...