Yes, I use walkthroughs. I like to experience as much of the full game as possible, therefore I don't want to miss any hidden bosses, dungeons, etc. Then there are games (I don't think any FF games fall under this category too much) where you really have to use a guide, because the secrets are so hidden or vaguely alluded to that the only way anyone would stumble across them is by accident or dumb luck. That annoys me.

Also, if I'm not sure where to go next or whatever, I find I'm better off using a guide than trying to do it by myself. The rewarding feeling of figuring something out myself does not even remotely compensate for the hours of pointlessly wandering from one edge of the map to the next, visiting every town and talking to every NPC until I find whatever I needed to unlock the next part of the game. I prefer to have fun when I'm playing a game, call me crazy.