Since I don't have enough time to write up a full review, I've just copy-pasted my brief review from Udacity's website below. Maybe I'll update this someday to a more comprehensive review of the program.
Overall I recommend this program if you're starting out with Android dev and need a structured guide to speed up the learning process - but with some caveats.
The strengths of this program are the various projects (especially the "Capstone" project where you work on your own idea) and the review system, all of which help to get comprehensive knowledge of the Android dev ecosystem. But there are some downsides, specifically:
The course videos aren't all that great, in my opinion. Now it's possible that my style of learning doesn't gel well with Udacity's style of video-making (lots of short videos, sparse on information). I like my videos packed with info, but I can see why others would like sparse videos too.
There is an entire project dedicated to making an Android Wear watchface, and although it can be argued that it's fun to work on, I don't believe it belongs in this program, which should be focused on Core Android skills. First of all, the Android Wear tooling (emulator setup, etc) is nowhere near as good as the regular tooling - you will run into all kinds of issues, many of which are poorly-documented online. It's an exercise in frustration, honestly. Second, I'm not convinced that smartwatches are the next big category of consumer tech devices - just look at the market performance of these devices. So making it a mandatory part of this program is a bit over-optimistic in my view.