What opinions have changed over the years?

Oh boy, let me see.
Gau-When I was kid, I used him a lot because I was a kid as well and he served me pretty well. Now as an adult, it just wasn't worth keeping him because of all of the Rages you have to learn to for him to carry his weight. But he still is fun to take to some areas and events but not everywhere, since you can't stop Rage and he will heal the enemy.
Terra-Terra was always a bit unsure of herself, and not my cup of tea as a character and obvious plot device. But my opinion has changed over the years. She is a talented sorceress and finally grows into a protective wall of strength for a bunch of children, even though she gets way too much special treatment in the game, her abilities really help the party through some situations, if you teach her the right magic and boost her stats she can really make mincemeat of a lot of tough bosses.
Locke-Locke was kind of just okay with me, he didn't really stand out much aside from steal(which for some reason has a low success rate sans Thief Glove. Later on as I got older, Locke had so much versatility, if you need a back row fighter he could do that, front row fighter, offensive juggernaut and he really shines in the end game. I just totally liked Locke's interaction with the group and his role throughout the story.
Sabin-As a kid, I bypassed Sabin because I couldn't figure out how to do Blitzes!! But that opinion has changed since I realized the cursor has to be pointing at Sabin. After that issue, Saban is awesome! He can cut through any enemy's defenses and just overpower everything in the game with his Blitzes. The guy is a great addition to any team.
Celes-always like her better than Terra, even more so now after Eternal Filena has a similar type of character.
Shadow-Shadow's awesome, I just hated him taking off when he felt like it, but his tragic backstory and relationship with Relm are interesting. Plus he is a badass ninja and his sprite looks awesome.
Mog-I will admit that I kind of overrated Mog to an certain extent because he is a cute little cat creature but his dances really aren't all that great and some of them can heal the enemy. I like to give him a Spear and DragoonBoots and make him a Jumper now. I don't use him all that much anymore, but he will always be a part of my final team in the endgame.
Setzer-This guy is kind of middle of the road, his backstory is tragic and interesting but he really isn't much of a character to take on an important mission. That isn't to sell Setzer short, though. He has the only airships in the game and he can help out a great deal since you have to utilize the airship as your form of transportation.
Edgar, Cyan, Relm, Strago, Gogo, Umaro, and Bannon-My opinion on them has remained the same, and that I don't have an issue with any of them.
Now for Kefka:As a child, I thought he was a jester or clown of some kind but as a I got older, I realized that he is completely insane and he creates a lot of trouble in the World. At one point, I thouyht that Kefka and Terra were in a relationship, but it doesn't seem like that at all now, he just used her as a slave. But he does manage to take over the world but in the end, it seemed like his bark was worse than his bite.