The ability for our team of developers at my work place, who are geographically spread all over India to collaborate without having to be in one physical location is fantastic! This has allowed us to have some great remote collaboration opportunities which were otherwise not possible as we had different time zones working together from around the world.
I do wish that there was an easier way to access certain features such as templates or customizations but this wasn't too much trouble when setting up new users initially. We've been able to use apprnda's services since it started out about 10 years ago now so they're pretty well established by this point & their support staff knows what you need before asking questions (which isn't always easy!).