Many people keep them and like them. My gripes are that when they are thriving, the reproduce. When they reproduce, they often wander and when they wander they often sting corals. My experience has been that in anemone vs coral battles, the anemone often wins. I tried putting one in my tank well before sensitive corals and I thought I was set with it's location, but it decided to wander one day. I would rate it as a 6.5/10 PITA. Shrug.
The frustrating part was that my clown wanted nothing to do with it. If you have a maroon clown (which is hosted by this species in nature) you may have better luck. I tried all kinds of crazy nonsense to get my clown to associate with my anemone.
Ultimately, my clown spent a year avoiding my anemone. Eventually I got a second clown. Within 6 weeks they both took up residence in my neon green candy cane coral. Looks neat. I'm glad they have finally stopped chilling by the return pipe.