Yeah, but it's not a history lesson. I mean, Jack Sparrow wears too much eye shadow and has a terrible English accent, but that movie was a great watch (the first one was, anyway). And who wants to see a movie about a guy who was already awesome at swords go rediscover his honor in a strange land where he gets just a little better at swords? The point is he refused to quit and he learned about real honor in the process. What makes or breaks a premise like that, imho, is the delivery. Cruise was great, one of his best performances. The main samurai actor is awesome in everthing, and the story was engaging from start to finish.
The again, I'm a simple guy. I get excited about Bruce Lee movies and and a totally clean tissue on the first wipe after a poop. I definitely go into every movie thinking I'll let it take me where it wants, so I don't overthink it. Also, I'm half kidding, everyone's taste's are different and to each their own.