I like that it's easy to use, can be used for multiple platforms (iOS/Android) as well is responsive which makes development very quick.
It also has good documentation so things are not too difficult when setting up your first app or project using this toolkit! Some of its features might seem hard at some point but they're really great once you get familiarized enought by them :) The only thing i don't think works perfectly in my opinion would have been if there was an easier way than adding all those dependencies manually every time we need one :). Using AngularJS framework + Material Design Lite gives us many benefits such as having everything set out nicely without any hassle from our side since most tasks could easily done via drag & drop functionnalities provided within MDL library itself!