I've been impressed with my WrisTech super-cheapie wrist monitor. Last couple of times I used it 3 times in a row. (Remember that the fancy computerized ones do SIX readings in a row, so there's obviously some "scatter" in the readings, even with a professional and $$$ monitor.) Both times, the 2d & 3rd readings were virtually identical, and the very first one was higher. I've never checked it against another monitor, but I'd be surprised if there's a significant bias. Despite being <$20 (and from China, of course!) and using only 2 AAA batteries for power, it seems impressive to me. I guess I'd be surprised if it survived more than a year of daily use, so if you're into lifetime monitoring a more substantial unit might well pay off.