Dart Frog Vivarium features

Really, neither. A water feature is usually more for the keeper than the frogs. If you choose to use one, it's generally less trouble if you just have a still water feature. Running water requires a pump. That means running electricity into the terrarium and this can be more trouble than its worth, particularly if your pump fails and it's buried beneath a layer of substrate.

I have no running water / pump setup in my mantella tank. It is heavily planted and they seem to get along well with the mistings I have been doing at the beginning and the end of the day. I keep their habitat quite moist with a false bottom. They aren't a heavy water related species like some toads. My oriental fire belly toads couldnt survive long in my opinion without the half land / half water setup I have for them.

I decided to do a running water feature in my tank that I am currently build up, and yes it is a vanity feature and not needed. However a feature that got my wife involved in the planning and building so I am ok with it. I have however run into the issue that John discussed in the past and had to tear the whole background apart to get to it. This time I built my enclosure where a dead pump is a 5 minute fix. I went with an external pump/filter system. water is filtered, and no electrical in the enclosure. Beats the 2 week fix on an old build that the pump was inside.