Dont think anybody will flame you, but you need to be a little bit more descriptive what exactly do you want to compare. I crossed trained in Hung Gar for a bit, I really enjoyed the work out it gave me, I was quite fit simply practicing Hung Gar alone. Where I practiced it, we did a lot of closed quartered fighting which was very good cause most good street fighters you go up against will prob be closed quartered guys, and this I could relate back to Kenpo. Not much in the realm of grappling, at least where i learned i must say, there was some grappling but quite limited, nothing like what you get in an MMA school or BJJ. Still a lot of very strong blows, punches and back hands, and a lot of conditioning and especially in the forearms, some sticky hands techniques. In fact I still incorporate a lot of the forearm conditioning I learned while practicing Hung Gar. The low horse stances where great also to build and condition your legs. In terms of sparring or self defense, i liked the sifu because he would break down moves to form techniques, but atleast where I practiced there were no techniques required to be promoted. Had to learn the form, spar, and do a horse stance for a certain amount of time.
As for Northern Mantis, I am not knowledgeable at all in that subject area.
