I have several Dart frogs and I find them one of the easiest of all my reptiles to keep.
I just made a another larger terrarium filled with exotic plants and will be adding more dart frogs when it has stabilized.
The colors of these guys are just amazing!
They are not good for handling so if that is what you want then I wouldnt reccomend them otherwise I find them to be easy once you have a humid friendly terrarium.