I've been fortunate enough to run into a few large in the yak. If I'm going to keep one I rope it through the gills and bleed it out. Made the mistake of bringing one on board and hammering it in the head, thought it was dead til it poked a few holes in my calf with the dorsal. Bleeding them in the water really helps the quality of the meat.
I really wish they'd go with a slot limit. I let most of the fish go but it's nice to keep one for a cookout now and then. I'd much rather keep the occasional fish that you know isn't going to make it when released than the breeders. Figure there's less crap in the little guys too.
Glad to hear you got into them.