We bought one of the "Cheap" RS instruments about 8 years ago. After a complaint from a large scaler about an airborne reading on his Byron P51 of 118 dbA at 100 feet, I took it into my lab and checked it against our B&K lab standard, used for our ISO 9000 compliance calibration of some expensive lab equipment. At a lab temperature of 79 degrees, the RS checked out within a +/- 0.5 dbA, fast response, from 70 to 120 dbA The cheaper price just means it can't be banged around the way the $1500.00 B&Ks we use in the lab can.

There's also a lot of subjective "Perception" about how loud one engine is compared to another, and a lot of people will trust their subjective opinion over an actual objective measurement. Regardless of facts! Just like people saying their brand X 60 turning an 11-8 prop at 10500 rpm puts out more power than a brand Y 60 turning the same prop at 11200 rpm. Folks, it ain't necessarily so!