I do not own the ThermoWorks Thermapen, but I have absolutely no doubt that is is the best consumer grade thermometer. After reading the discussion in the other thread I decided to post a review of the RT301WA for those that do not have the desire, or possibly the means to spend just about $100 on a thermometer as a reminder that the rest of us can play on the same field as those that do. The RT301WA is currently on sale at ThermoWorks and Amazon for $16.
I have owned this model for a bit over three years now and I could not recommend it more highly. I can tell you it is dead-on accurate and very fast to read. In fact, if you look at advertised specs, its accuracy is within 2/10ths of a degree, and its read time is within 2 seconds of the Thermapen. I can certainly live with that. I regularly test and calibrate my thermometers, and I have never had to adjust the RT301WA. It has always read exactly 32deg in the ice water bath. Never 1/10th high, or 1/10th low. This thermometer is fully waterproof, so no worries if you accidentally dunk it in something and have to clean it, and it has a battery saving auto-off feature for those like me who regularly forget to turn it off when done. Cook's Illustrated magazine rated this thermometer as a top pick, and as an owner it is not hard to see why.
On the subject of battery life, I want to say that you can disregard the past negative reviews and comments on this. After twice replacing the battery in the first year I owned the RT301WA, I called ThermoWorks and they explained that the first version did indeed "eat" batteries, and they had updated the model's internal circuitry and are now shipping with a better battery. At no cost, they immediately shipped me a replacement and I have yet to have the battery fail in more than two years. Proof again, that this company stands behind its products and is committed to customer service.
If you are not 100% happy with, and confident in the thermometer you are using now you should seriously consider replacing it with this one.