The problem with these devices is that you get consumed by information, spend a ton of dough, and tell your friends, ooohhh, ahhh, look at this information.

Do yourself a favor, buy a porn mag and bring it to the field. Your pals will be much more impressed

I consume myself with information that is useful, and extrapolate the rest. Useful as in an AMP meter when setting up my airplanes.

Mileage may vary, but you are right, I don't have one, and I don't recommend them. I know for a fact my airplane won't go 200 MPH with 36 lbs of thrust, so retarding anything to meet the rules is not necessary.