You actually have as long as you want to make up your mind, the only downside is you'll have to pay $99 more for an OS upgrade you don't need. Win 8.1 does everything that win10 does--in fact slightly more--although win10 is certainly more polished. It will be many years before you'll find a program built for win10 that won't run on win 8.1.
The hairbrained boosterism to upgrade to win10 does nobody any good, and stupid slogans regarding "tomorrow's wonders" or "keeping up with the times" only serve enrich Microsoft at the expense of actual functionality.
Nobody here has been able to tell the OP what she's missing by not upgrading to win10, and the reason is that the OP will only be missing out on enforced privacy violations as the win10 EULA makes clear.
