DO NOT install v9.3 if you have an iPad!
Many people, including me, are reporting that this update causes your iPad to be stuck on an "Unable to activate. Please try later or connect to iTunes" screen. And if you connect to iTunes, it still does not activate. If you boot into Recovery mode and attempt the 9.3 update again, iTunes will tell you to try the 9.3 update, download it, apply it and still does not work. Mine just finished restoring to 9.2.1 right now, which is the only reported fix.
While I have an old iPad 2 people are reporting this on various models including the much newer iPad Air 1.