Great, except for Git integration
What do you like best?
Connecting to/from Google services is very easy. Spinning up new instances is quite fast, and you get all the goodness of Jupyter notebooks.
What do you dislike?
Ungit has one of the worst UIs of any product I've ever used. There are too many steps needed to get to the command-line git for my notebooks. I've sometimes had my SSH key for my instance stop working and have had to delete it, resulting in loss of work if I haven't committed my notebook to git.
Recommendations to others considering the product:
Would definitely recommend it if you are storing most of your data in Google Cloud already - ease of connection between Google Cloud Storage, BigQuery, and other services is the killer feature.
What problems are you solving with the product? What benefits have you realized?
I use Datalab for testing my deployed services and for doing data exploration and analysis. I also use it for presentations involving code.