[andreiv]

I also think it's an improvement but I wouldn't call it "huge". My biggest problem so far was the lack of "support". By that I mean that a simple to medium difficulty Flat Design project does not require a lot of transitions/animations work. This in turn means that the development time is kept relatively low. In contrast, Material Design emphasizes these visual features.

In my opinion, this framework is the missing piece for MD. I only wished that Google had thought of that and helped speed up the development process.

[ARussell]

It's just my opinion, but I still think it's a huge improvement. The oversimplification of flat design sort of put it in an "uncanny valley" of sorts for user interfaces, in my experience. I'd look at a UI and really have to ask myself whether I should be able to click on an element or not.

[Navarr]

I see where MUI fits in, but I think Google is also using Material Design to drive polymer and webcomponent adoption.

Being able to import a few elements and make a resizable toolbar is a much better experience than adding a fucktonne of classes, in my opinion.