Ever since upgrading to 7.1 from 7.0.1, the iOS simulator constantly hangs for 10+ seconds. It makes developing on the simulator painfully slow. Building on an iOS device doesn't have this issue.
iOS Simulator constantly hangs
It seems that other people are experiencing the same issue:
I am also experiencing this issue ever since updating to 7.1.
It seems to happen intermittently, especially when several touch events are being registered rapidly on the device. The hang will last for 10 seconds or more as the OP describes.
I've tried the new XCode 7.2 Beta in hopes that this issue has been addressed, but the same problem persists.
Happens to me also in Xcode 7.2 beta