Just reached the part of the game where you pick up the second extra team member (Sveta). Anybody using any of the extra guys instead of the original team? So far I have just sticked with staying with my original dudes, kinda tempted to swap for Sveta. Feel free to list your current team. 

Actually it's not just a matter of opinion. Some characters are just better than others. Like take Rief for example, he sucks and should be replaced as soon as possible.

I replaced Rief straight away. In the lost age I cycled everyone so that they were around the same level but I can't be bothered with that sort of thing nowadays.

I'm keeping the same people. It doesn't matter much to me because they all level if they're in the party or not. People say Rief is weak, but I'm sure he has some strong points. He has to.

I really didn't like any of the second set (other than Amiti) until I started using them. By the way, Sveta has some of the coolest tricks in the game, including her "transformation" psynergy. She is totally worth using, whether its at the expense of your other wind user or someone else. Because having one of each honestly isn't that important. 

" @AgentJ: I was going to use her but she left my party, I'll use her when I get her back. Also what was your party then if you didn't have one of each element?
 
@RoxasXIII: I haven't died yet either, which brings me to one of my complaints of the game being a little too easy. "

Final time: roughly 36 hours, after beating the toughest boss in the game (spoiler: it's not the "final boss")

I swapped out Rief for Amiti as soon as I could. But that was out of the personal preference because Rief is a girls blouse. 
I beat the main game in about 27 hours. 
I don't think the game is less easy than the older ones. If you walked in those you were able to rip people up and I didn't play through the game with all my Djinn on standby like I did when they first came out.