Custom transitions : MaterialPageRoute vs PageRouteBuilder

[Michael Tawiah Sowah]

on this page https://docs.flutter.io/flutter/widgets/Navigator-class.html

"Custom routes

You can create your own subclass of one of the widget library route classes like PopupRoute, ModalRoute, or PageRoute, 

to control the animated transition employed to show the route, the color and behavior of the route's modal barrier, and other aspects of the route."

yet all the search I have done about a custom route and custom transitions has led me to MaterialPageRoute samples.

so I am trying to understand here, what the recommended if any? and whats the advantages with either here? 

all am trying to do here is custom transitions for my page navigations.