Dwarf angels of any type are a gamble. Some are model citizens and others are the bane of your tank. You will find people here that swear by them and others that will say never get one. Personally, I had a lemon peel angel, beautiful, best specimen I ever saw. Then he destroyed my birds nest in less than a day. Was also super aggressive. So off it went as much as it pained me to do so. Months later I had to try another dwarf angel and I got a potters angel, where some say they are the least likely to nip at corals. Decent citizen to date, nips occasionally but nothing the corals can't handle. So I'm still holding on to him, but watching for any sign of following the dark side. Pygmy's will be another dwarf angel that is a gamble. Personally, I love dwarfs too much not to try them out. They are amazing fish, just have an exit strategy if they don't pan out and be sure that you are willing to take the gamble.