For me the value of a thermapen is not that it tells you if something is "done." What makes it valuable is that it tells you exactly how done it is within seconds. That may not mean much if you don't cook to exacting standards. But if you do then it may be the best $100 you'll spend. I use mine for lots of stuff, including beer brewing where I have to know the temp of my strike water to within 2-4 degrees and the temp of the mash. My wife also loves the thing. It was hard to pull the trigger, but now that I have I'm glad I did!