Ever since I installed the Xcode 7.3 update last night, working with Storyboards has become a nightmare. Simply changing the 'hidden' property of a UIButton takes 30 seconds now. Really not sure what changed, but it makes UI updating almost impossible.
Device specs are here: http://i1332.photobucket.com/albums/w602/Donnie_Wittbrodt/Screen%20Shot%202016-04-02%20at%201.03.25%20AM_zpscefz7zwo.png
I've uploaded a clip here (I click the hidden property and you can see how long it takes): https://youtu.be/uB5VvXEv0_U