Product review (5 stars): Very Accurate and Very Quick
Amprobe has a reputation for making high quality tools for professionals, and this is another one.  Designed for HVAC professionals but useful in many other professions, this unit will give you temperature and humidity readings that are much more accurate than others.  It seems very accurate and very quick to adjust its readings, showing easily temperate differential just walking across a room or from the ceiling to the floor, and doing this in a matter of seconds (as long as the swing isn't too large).  It doesn't have a probe to allow for attaching to anything (i.e. spiking wood to figure out the humidity/temp) but it works great for air temp/humidity readings.

My unit did come with a dead battery which caused a little bit of concern, I thinking the unit was dead on arrival, a fresh 9v got it working right away.