I too have been reading about hand guards and getting your hand trapped in a over the bars incident.  I ride dirt and road, probably about 60% dirt.  I am going to go with either the zeta or the cyrcra bend models because they just look less likely to trap my hand.  I can see how if you had a bad wreck (hitting a car) and went over the bars with your had trapped, you could possibly tear your hand off.  It is weird how I am so paranoid about this stuff.  90% of the time that I ride the road all geared up I see countless idiots who are riding with shorts, flip flops, a tank top, no gloves and no helmet.  Ignorance might be bliss, but it can be deadly or at least painful when riding a motorcycle.