Hi have a Dakine Fusion Seat harness and it causes me a few problems - I think because I am a girl. It use to give me bruises just under my ribs but this has stopped now that I am getting better and don't have the kite at 12 so much.
I still find that the straps that keep the bar/hook in place need to tightened after a couple of runs though I cannot get them any tigher while standing on the beach befor I go out. Like I said I think this is because I am a girl and they are not made for girl shapes eg in at the waist!

I had a look for another harness but all the girl ones seem low at the back and dont have so much padding from the bar on the front.