Others are probably getting picked off around you because they are bigger idiots. Most often if a cop can get more than one violation they will take that idiot.
It is a myth about composite or fiberglass front ends not reflecting radar signal back to the unit very well. Doesn't matter if a Kenworth, Raptor, Corvette or Vespa they all reflect the radar.
The size of the truck shouldn't matter either, vehicle size isn't a factor in visual estimation.
I have had my truck since April 2010 and haven't been stopped once and I still drive like I could have gotten away with before retiring. I have been warned lots and eyeballed countless times. I don't think it is the truck, it is the idiot driving.