An interesting issue I'd like to see fixed: There are certain websites that just refuse to load on Safari in 9.3. Like homedepot.com which just displays a white screen, and the search functionality on lowes.com is broke too. I can look up both websites just fine on my devices that are still on 9.2 but on my mobile that's running 9.3, the sites are broken. If I load up the chrome app both sites work just fine.
are you using purify or another ad blocker? if you are, tap and hold the refresh button in the top right hand corner of safari to reload the page without ad blockers. sometimes even youtube videos get blocked for me on sites.