Personally, I like the open world options more than linear ones like FF10.
I'm probably the opposite. I like the more linear aspects, because I think it lends to better storytelling. Maybe that's why FFX is my favorite. In fact I thought FF6 and FF7 would've been the best until they opened up more, then they kinda fell apart IMO. Like I thought FF6 really fell apart in the world of ruin, and FF7 fell apart after disc 2.
Its odd tho, cause I've been playing ever since FF1 (the 3rd RPG I ever played behind Ultima and Dragon Warrior for the NES). And FF1 was mostly about exploration, and very little about story. Its funny how the series (and my tastes) have changed, but I actually like the storytelling aspect of it more than the exploration part of it, now. I think that's the strengths of FF4, FF6, FF7, FF8, and FFX. And I think those games are the cream of the crop.
All a matter of preferences I guess.
Anyway, in FF13's defense, I'm on chapter 11, and it really opens up there. There's a huge world to explore, and its a lot of fun. There's a hunt system kinda like FF12's, and its a blast. I need to go ahead and finish cause I like the story and the characters, but exploring is fun too.