Coral Beauty or Bicolor dwarf angel

[Aveet]

Has anyone had experience with both of these fish? I'm looking into them for a 50 cube reef tank. Do they tend to only nip at corals when they're underfed or just out of boredom? Would they do well in a low stocked tank of my size with a protein skimmer rated for 150 gallon tank?

 

[Cliving1]

I have a coral beauty in my IM40. Definitely needs more room, or length I should say. Once I upgrade I will never go back to a cube. Personal opinion. Mine nips on any fleshy type like a favia. Does not matter about being full