Here's my take on digital thermometers. They are the same as today's TVs. Doesn't matter how many good ones are made their will be bad ones also from the same manufacturers made the same day from the same plant. Some TVs come with dead pixels, some don't. No matter how well made an item is its mostly the luck of the draw.
That being said, my digital Thermometer is around 10 years old, its consistent delta T is plus or minus 5. After reading most folks problems I seem to be lucky I guess. But I also figure that only those with problems do you ever hear about.
Mine is a Maverick Redi-Chek, ET-72. yes its old in electronic life spans, but it works every time I use it. That's a good thing. I like simple. Its easy, its accurate, it works. Its a keeper.