This session's major learning curve was that the DM bought the Monster Manual as a Roll20 resource. Now he can pop in fully statted monsters with a mouse click. The downside is that, as near as we can tell, it has to be integrated at the start so he had to start a 'new' campaign so all our character sheets got wiped out :D
For me, the amazing thing that Roll20 did was enforce lighting conditions and vision restrictions. My fighter is the token human in the group with three of the other five member having some kind of dark vision.
So, when the Goliath bard, the only other character with normal vision, moved away from me with his light spell, I was suddenly in the dark. By the time I lit a torch, it was a struggle to find the rest of the party. Since everyone else was either less affected by the dark or had their own light source, I'm pretty sure no one else knew how blind I was.
Frankly, that was awesome. Kind of frustrating at the time but still awesome. Roll20 allowed each of us to only see what our character could see so the other players had no idea how lost I was in the dark. It was more 'realistic' and will make coordination more important in the future.
Oh, for anyone that cares, the campaign is set in a fantasy Norway and we finished cleaning out a cave lair of goblin raiders and their orcs mercenaries for the local lord, although the goblin chief got away. And, since we're using milestones, everyone is now second level.