We use an avianweb mini that came as an extra with our mini bator. I just calibrated it (stuck it in a baggie and then did the ice water method) and it was only .2 degress off . I like how small and portable they are. You should try calibrating yours!
(I didn't actually change the numbers on mine, I just wrote how off it was and do the math to make it the appropriate temp.)
Thanks! I Will calibrate it. I Do like the size of it also.