You should upgrade but the free upgrade offer is good for a year, so I would wait a few months before doing so. Windows 10 solves a lot of the problems that people coming from Windows 7 had going to Windows 8 (8.1 also solved a lot of those problems). But like all major releases there will be a period where the drivers don't quite work or aren't available, and the bugs start getting resolved. Waiting 4-6 months will get you past some of the pain that others will feel.

I've played with some of the pre-releases (they are available to the public) and it is looking nice but still not ready for prime time.