Well, after having done this test, I took the old vest, which has the same reflective material as the LED one indicated above, and threw it out, because as you can see, compared to the new one, it's like the old one isn't even reflective at all. I thought my old one was good too until I put it side by side with this one.

I'd look forward to seeing actual tests with an LED light. If I can find one locally where I could test it then return it (because I don't expect much from it) I'd do the test myself. I still might if I decide to spend the $20. I don't expect to ever use it though so I'd just be spending $20 on curiosity.