I too used PSP 9 for years - never bothered to upgrade as it did (almost) everything that I wanted...but then I succumbed and bought CS5 and I'm loving it. It takes a while to get 'into' where all the different tools are but once you do, you'll wonder how you managed before.

When I first started using CS5 I used to open PSP to finish an image as it seemed so much easier and quicker (because I knew where everything was) but I persevered and although I've still loads to learn, I am amazed at the power of the program. Stick with it and you'll love it too :)  Good luck!