Settsu and Kawachi were Japan's first dreadnoughts, sort of. You see, they had 12x12" guns, but ... they weren't all the same length. Go fig. I don't get it either. Must be some kind of chibi thing.
Kawachi has the same 28 second speed as the Nassau, but with even fewer shafts. Two, to be precise. Goodbye acceleration.
Kawachi is short and kinda tubby, but only has a single rudder so she won't handle as well as the Germans either. Not terribly, mind you, but not great either.
Kawachi has a relatively low freeboard, flush hull with casemates, so that's something. She's not exactly easy to hit.
Kawachi is a simple ship, but lack of a kit and plans availablity means a beginner would have difficulty. On the other hand, a skilled battler would be frustrated by her relative lack of maneuverability and slow speed.
I've only seen one Kawachi, and while it was okay, that's about the best I could say for it. Unless you're a die-hard weeaboo, you'd best stick with ze Germans.