Hi Earwax- [sorry for the length!]
I didn't upgrade after 8.5 because I didn't have the hardware to handle it. The laptop I have now I inherited from my Dad and it sounded like it could handle X3.
I still have no reason to think it can't, since I haven't done anything at all to push it. I've literally just been playing around with some features to get myself accustomed to the workflow and reacquaint or acquaint myself with some of the views, navigation techniques, et cetera. I've done no audio recording at all, for example. All of the hangs I've gotten have been with tiny "That sounds interesting. I'll just try this" projects.
I'm running a clean Windows 8.1 install with none of the bells and whistles that came installed on the laptop.
I've been a Cakewalk user since the early DOS days and I was hoping to get back to it with X3e and my current setup, but it doesn't look like that's going to happen. You shouldn't take my experience as any indication of what yours might be, however, since as you say, there are plenty of users who aren't running into any issues with X3.
It would be different if the hangs I'm experiencing were with projects with tons of effects and where I knew I was really pushing it, but they come up all the time doing the simplest things.
For example, tonight, going through the Browser tutorial in the Help file, I got to step 4: Click the Media button, point to Synth Preview Output and select Cakewalk TTS-1 1 on the submenu. Selected Bangin 10.mid and got a hang. That's just not right ;)!
As I said before, I'm sure I'll keep playing with it because I really like a lot about X3, but for whatever reason, it's extremely fragile on my system. I've never had a hang or anything like a "motor boating" sound with my current primary DAW, so I'm not ready to chalk it up to inadequate hardware, settings, etc.
Thanks-
-Susan