No comparison when it comes to the technologies used. Aeroperfect uses Optical Encoder technology which yields highly repeatable measurements. AnglePro, while a low price, uses a capacitive-type measurement which may be susceptible to accuracy drift with temperature. Do a search here on RC Universe and you'll find that some users have found errors as much as 2.3 degrees when measuring a carpenter's triangle. Don't forget the .05 degree resolution of the AeroPerfect covers +/- 180 degrees! It will handle the most extreme 3D throws without any repeatability issues. Capacitive type meters have a limited "sweet spot" when it comes to accuracy and repeatability.

The Budd meter requires a target to be located at precisely the right distance away from the laser in order for measurements to be accurate. Plus its ranges is quite limited. I'm not saying that these other products don't have their place in the market- just don't sell the AeroPerfect Meter short. I believe it is the most accurate and useful meter you can buy.