Product review (4 stars): A little slow to update
I find it very helpful to have a tool like this around.  Not only for measuring ambient temperature and humidity, but also for things like seeing how well the A/C is doing either in my house or my cars.  This can tell me if my refrigerant needs recharged.

The tool is well made and seems fairly durable.  It's not bulletproof, and a drop off a ladder or something would worry me, but I don't think I'll be using it in that fashion too much.  It does come with a case, but it's a pretty cheap looking pleather/vinyl type of thing, and the instructions don't fit inside along with the tool.

It's always sensing and adjusting in real-time, so it doesn't really "lock" onto any readings.  You basically have to make a judgement call when you think it's stable.  The temperature takes much longer to bring up to stable than the humidity.  Going between wide variations in temp will require a few minutes for it to really adjust and stabilize.  The humidity is better and usually stablizes in under a minute.

I do wish it had a backlight, faster response time and a nicer case.