Ionic CLI update

I’m building an Ionic 3 app, and each time I run ionic cordova build android, i get the following prompt:

The Ionic CLI has an update available (3.20.0 => 4.2.1)! Would you like to install it?

I’m reluctant to update, as I don’t know what impact it’ll have on the app, so I always choose “no”.

Has anyone updated yet? If so, how was your experience? Is it the same as Ionic 4.0?