I agree on the releasing concerns FISH. During the spring, it's not as much of an issue. Water temps are pretty much the same from top to bottom. During the summer, the kokes are down in 50F water and get reeled up into 70F water. That's a tough change, and one they don't typically make on they're own, especially the big fish!
If you think about it, how many kokes do you catch with hook scars? My survey size is smaller than most anglers on here, but I have yet to see one. I catch bass, rainbows, and macks all the time with jaw damage or hooking scars. I think they handle the changes a little bit better, and mortality isn't as much of an issue.