I have now done 2 more chapters of Final Fantasy XIII.  Still liking the game.  The character development/story progression is great.  The default difficulty seem about right.  The boss fights require strategy, not just appropriately leveled characters with the best equipment.  The save points are appropriately spaced so, I can sit down and play for a little bit then stop.  My biggest complaint is the length so far.  I would prefer shorter, but that is mostly due to my own time restrictions.  If I had more time to play games, I think the length would be right.