Chapter 3 is probably the longest chapter in the game. Chapter 4 is pretty long too though. Then the final chapter is the last dungeon. I'm guessing maybe 2/3s.
I would say probably Zero and Ao for sure. That game is as much a sequel to those as it is the Cold Steel games as the plots of those two series have joined together. I would argue that the story and characters from the Sky series are better than Cold Steel. Zero and Ao are about on par. If you made it through the third game and all the references didn’t bother you I guess you’d be fine. Having Tita around in CS3 for example was nice because that’s a main character and party member of the Sky series. Same with Agate but he was in 3 far less. Olivert is probably mostly lost on you as a character if you didn’t play the Sky series.
I played the early fan translations of both Zero and Ao and don’t regret it. Ao’s translation seemed better than Zero’s but the Geofront one wasn’t out back then. It’s probably questionable if the revised Ao gets released before CS4 if that comes out this fall.
