I just purchased PD18 Ultimate and I really like it. It's a totally separate install from my PD17 product, and judging by the 365 issues I'm reading about, I'm glad that I stuck to my process of always purchasing a clean copy of stand alone software of this nature. I'll keep PD17 on my system for a while in case of bugs in PD18 that I don't yet know about, but it seems very stable to me. The new bells and whistles are cool, but I do wish that they'd offred the functionality of selecting the precise number and types of tracks for each new project. I know that you can remove empty tracks, but that's not the same thing. Other than that, it's working very well for me so far.