I haven't used the North Hadlow bar personally, but I had a good look at one a mate was using. IMO best bar I've ever seen. Only problem with this bar is the price!!! I ride Wainman C kites, but I'm thinking of running one of these bars on my kites.
Short bar, with several easy adjustments at the bar. You can ride suicide with an option to connect to the 5th line. So if you release the loop while hook in (accidentally like has happened to me in the past), the kite flags out to the 5th line (so you don't lose the kite). Personally I wouldn't ride a C kite without a 5th line purely for easy relaunch in light winds. But for performance, the North bar is a loaded 5th line. That means no matter how much you depower the kite at the trim handle, the leader and 5th lines don't change in length. So the kite tension on the leading edge remains the same. Better flying. Above bar depower all the way.