Should I ugrade to windows 8?

I'm sure there's been a few of these threads before in this forum, but I couldn't (didn't feel like) looking back for one.

Here's the situation

I have a Dell XPS 15z (read, not touchscreen), and it's beginning to run slowly, and I have a ton of crap and unused programs and maybe even some worse stuff on it.

Right now I'm running Windows 7, and my original plan was to just to get a fresh start and reinstall Windows 7 again like I have in the past.

However, I remembered that I have an unused copy of Windows 8 that I got for free while I was in college through some Microsoft program.

The question is, should I just stick with the old Windows 7 that I know, or is this the perfect time to make the jump to Windows 8? Thanks for the help.