Awesome desktop and mobile usability and design. It helps you increase productivity with some really handy features that saves and organize.
There is not friendly way to attach and image and assign a link to it (there is a way but you need to dig and research on how to do it.
It took me just 4 days to get used to it coming from traditional gmail desktop tool.
But once I could manage the initial learn curve, it really improved my productivity specially with reminders, smart suggested answers and how it groups different kinds of emails automatically.