All the interfaces look similar, so getting used to working with them should be pretty easy.
The dice roller looks easy to use and shows a very pretty d20

The change map interface is easy ... maybe it needs a bigger preview thumbnail ... time will tell

I love the visual aid possibility ... send treasure maps, pictures of monsters, items, charts, etc ...
Send audio is a very cool feature I will probably use extensively ...
Looking at a chart will open the chart in another window? That would be very cool. Just open the charts you need for that session. Get more charts if needed.
The preference interface is easy to use and gives nice options.
Contextual menus rock


Deploying figures looks easy to do ... especially using the same interface.
The unit settings look great ... what a cool way to use different settings for the same creature for instance.
Ah ... you already tell that with a rat example LOL