When this type of thermometer first came out for healthcare professionals, we tested it's accuracy for several weeks, as compared to esophogeal temp probes (stuck down the throat while intubated for surgery). It is just as accurate as the esophogeals, digitals, both rectal and oral, and more accurate than a tympanic (ear) thermometer. I was extremely pleased when it came out for the public. My 2 1/2 year old screams bloody murder when we try to take his temp when he's really sick, (he'd play with it if he wasn't sick--big clue to us that he WAS sick)and that was trying under the arm. With this one, he can "help" mommy by holding it with me, and I trust the readings I get with it, since I personally helped test it in the operating room. The only thing, as was true with the tympanic (ear)ones, it is a little expensive, but well worth it just to not fight with the child to take a temp. The tympanics are very easy to use wrong, as you have to pull the earlobe the right way, and anyone who has had or has attempted to take a rectal temp, we KNOW how that can be, especially waiting for the thermometer to read.
Take the extra money to buy it, it is well worth it!