As Visual Studio has become more extensible there are more and more extensions that developers like to install. Unfortunately not all of them are well behaved. The more extensions you install the more likely VS will crash or slow down. When this happens most people tend to go to the forums and complain about VS bugs and/or performance. Yet the culprit is likely an extension. Up until VS 15 preview 5 there has been no easy way to diagnose this. Generally, when responding to a forum post, a user is recommended to run in safe mode to eliminate the chance that it is an extension. But doing this doesn’t really help narrow down the problem that much because: 1) the problem may not occur very often and 2) many extensions are critical to doing real development.
In VS 15 Microsoft has finally added some performance monitoring to VS. VS has had perf monitoring for a while but none of that was visible to the average user. In VS 15 you can now go to Help\Manage Visual Studio Performance and get a window that provides some basic information about extensions and tool windows, the two most likely causes of a slowdown. This window allows you to see if an extension or window is slowing things down. If so then you can disable it and report the issue to the author. Hopefully this will cut down on forum posts but we’ll have to see how this feature evolves until release.