The Thermapen One is very nice. I bought the Operation BBQ Relief version both because I support OBR and because I think the graphics liven up the appearance.
I hope to do a comparison - maybe even a video one - of the popular instant reads out there. In the meantime, I will say that I have long been - and still am - a proponent and even a fan of the attractively priced options from ThermoPro. They are a good company, with legitimate support. Their best products are solid performers. I will admit, though, when I got my Thermoworks Thermapen One I could immediately “feel” the difference. It is hard to describe but very real.
Not everyone needs a One, though. I will still say that the $15 ThermoPro TP-19H is very solid and will do all most users would ever realistically need. Now even available in three colors!