Constantly looking at those old scratched out serial numbers on Apple products is a nightmare, but with the ability to add light and a very magnified glass to read it, it's a breeze. I totally recommend the loupe. It's a little heavy, but it has the cover to protect it and tuck it in, as well as the little hook so you can try to hand it to a key right.
Was able to spot counterfeit products immediately.
Will need to have a utility belt to carry this loupe around. It's heavy but very convenient.