@jordan I think there’s room for both. The Thermapen is unexcelled for fast, accurate, portable, measurements but there’s no way to use it for remote reading. The ChefAlarm is a little unhandy to hold, you have the cord to mess with (the sous vied’s probe wire is a lot more flexible), and it’s not as fast as the Thermapen. But, if cost was an issue, I’d go with the ChefAlarm.
I also have one of the original ThermoWorks oven thermometers (now discontinued), and a nearly identical Pyrex version. These are available under several names, usually around $20, and I’d be sure to keep one around. My baked potatoes WILL come out at 210 degrees while the APC delivers a perfectly cooked steak.
I’ve had no problem with the APC’s thermal control and I don’t really expect any. The old Cold War motto seems appropriate, Trust, but Verify.
Tom