they are the best eating IMO.
As for returning them it depends where you fish, 30 yrs ago i remember fishing in a lake near wanganui that you were asked to toss em up the bank if you didnt want them. I think it was because they were ileagally released and numbers had exploded.They can get to plauge preportions but mostly I don’t think there is a rule about releasing them.
Next time you get some decent ones try them sashimi. fillet chill till ice cold slice thinly on an angle then dip in a mixture of soy and a little wasabi its magic