Got my BelOMO 10x loupe in the mail last week and used it last Friday. Definitely a step up from my other loupes.

All of the loupes that I have tried have the optical property of the magnification power varying with the distance from the object being viewed. I typically adjust this distance to close to the highest magnification before distortion starts being a problem.

The beLOMO seemed to deliver close to it's advertised power before distortion. The cheaper loops that I have experimented with have a laughable amount of distortion when used close to their advertised magnification