Don't Install If Your Device is Important for Work or School
If you discover the Android Marshmallow update right before a big work presentation or school project, our advice is to hold off until after you get whatever you need to get done done.
If you haven't updated your apps in awhile, there's a chance they will start acting up after you install Marshmallow. There's also a chance they'll start acting up even if they've been updated recently. We're already seeing a number of complaints about apps problems.
The last thing you want before a big presentation or meeting is for your apps, Exchange, or something else to go haywire.
Before you install Marshmallow, dig into app reviews and feedback from co-workers and your IT department if you have one.