So after watching TomtheGeek's stream a couple of days ago, and after having so many issues with the consistency and usability of one of the earlier Win10 Tech Previews, I was honestly sorta worried about Windows 10 and what upgrading would mean to my daily use of my computer. However, two things came to mind after reading this pretty good review:
http://www.techspot.com/review/1037-windows-10/1. DirectX12 is only on Windows 10. Immediate sign on right there.
2. Most people consider 8/8.1 to be a flop, however I can say that I've never enjoyed using an OS more than 8.1 with Start8. And really, it seems like 10 is just going to be a massive improvement on that experience.
Sure, the first few weeks or even couple of months are going to be rough. Updates will probably be consistent in fixing issues as soon as they're reported on reddit or Windows Insider forums or whatever the forget. But all in all, its the future of Windows, and I'd hate to be sitting behind on a deprecated version of Windows simply because I'm more comfortable with it.