I didn't get any of the ones you're referring to, but I have had my Potter's Angel for about a year and a half. 1hr drip acclimation, then hang bag in tank for 15 minutes to equalize temp, then turn lights off for a while when introducing to tank. I always feed frozen mysis, and alernate between frozen spirulina-brine, frozen mega-marine, frozen mega-marine-algae. I also feed cyclopeeze once or twice a week. He's so fat that he swims funny.
Also of note, my tank is very established. When I look at the tank with a red light at night, there are thousands of little critters running around all over the rocks. This undoubtedly helps, as Potters Angels constantly scour the live rock for food.
I have never had him bother any of my softies, clams or sps. I'd bet that this would not necessarily be true of other individuals.
Hope this helps!
150 drilled. 3x250w 14k MH, 2 superactinic VHO. Reeflo Orca 250, 1/3hp drop-in, 16w UV, LR, SPS, Fish, Softies. Austin, Tx