It is a good feeling! Generally I've found that most people are cooperative if you politely explain what needs to be adjusted and why. Occasionally, though, you'll run into those people that give up on an app or even quit the site if their character doesn't get accepted as is, and that's a sucky feeling, especially if the character they were working on looked really neat. Then again, if someone gives up on a character app just because a mod requested some changes to better fit within the site setting, they probably weren't that committed to playing that character anyway.