MT, IMHO those guy's riding with their toes pointed down are asking for trouble, oxbow's or not. A more level foot yes, and it is harder for me to acheive a heel's down position with 'bow's, but toes down is asking to go out the front end. As to technique, the 'bow's make it easier to que your horse with your spur's, and that is the only time I think toe's should be pointed down. With flat bottom stirrup's, I probably ride with too much foot in the stirrup, but I can still more easily acheive a heel's down position.