I got the $28 deal, too. Thankfully I had Discover points, so the final cost was $-0-. It will be a Christmas present for my nephew.
Bruno,
Like Bruce, I have a Thermapen One (
BBQ Relief edition) and a ThermoPro Lightning. I hope to do my first YouTube video this summer (hah!), and comparing these is what I want to try to record. I plan to come at it from a different angle, not replicating the simultaneous plunges in ice water and some other stuff that has already been well covered but instead focusing on the "look and feel" that you were mentioning.
From all I see, both units register virutally at the same very quick speed. To me, the Thermapen One feels sleek and solid. In car terms, I think of it as a Mercedes coupe. The Lightning feels, to me, more like it is ready for a workout with a rough and ready attitude. In car terms, I see it as a Land Rover. I like and use both of these thermometers, and I think which one a person might prefer may parallel which vehicle that person would choose among my analogies

.
In lower light, the Lightning is a lot easier on the eyes. In bright sunlight, the One is easier to read.