If your device is working as you want and need, why risk the update? In most cases the OS updates are minor bug fixes. Read through the forums and see all of the issue people have when they update. But of course, we only get the bad, rarely the good.
If you insist, make a good backup before you run the update. Keep in mind that some of your downloaded apps might not work with the new OS and you will have to download and install newer versions. Plus some may not even come back using restore and will have to be reinstalled.