Phillip, all of them have acted about the same. First trip they seemed to work fine. I would use them on maybe four or five quarts. I get home, remove the batteries and store them in a good place, dry etc. Another outing, batteries still quite new: push the button once or twice, according to amount of water. Most of the problems have come after the light blinks that it's ready, I put in in the water and either the red light ( depending on model) or sad face comes on. I would dry it and start over. Sometimes after a half dozen tries it would work, sometimes after a dozen, sometimes not at all. Next morning could be fine, or not, about 50% chance. Other times the problem would show the moment I pushed the button. I was careful to keep the probes dry, not get any other part wet, store it correctly, not drop it, buy the recommended batteries etc . It has been a very frustrating experience for me. I never had any problem at all with the Classic, then my search for lighter gear made me sell it to buy something that did not work, again and again and again.
edited to clarify that by "keeping the probes dry", I obviously don't mean when i am using it, but after I use it and put the cap back on, and in between tries when it's failing me.