No matter how well maintained, they are still horribly outclassed by any modern navy. And I'm betting they ain't maintained very well either. Having rust up on your hull during a publicity shoot doesn't exactly inspire confidence. Any brass I know would have reamed someone up one side and down the other for that.
And then we have the issue of training. Even the best piece of equipment is only as good as its skipper and crew. You gotta remember, the NORKS aren't exactly known for encouraging free thinking. That is what makes U.S. sub skippers so good, is they are basically turned loose on their own to prove themselves, and if they can't cut it they get canned. Saw it myself several times. Aggressive tactics are encouraged. They are wolves.
