Product review (5 stars): High recommend - a bargin for this level of accuracy.
I've pleasantly surprised how accurate this is for the price. In the past I've had quite poor luck with humidity monitoring (or at least the level of updates and responsiveness) but this one is indeed highly accurate and very responsive. I would agree that it is with +/- 2% RH and I feel many competitors fail to even get to  +/- 10% RH. I also found that the measurements were fairly close to real time - the literature mentioned it measures conditions every 10 seconds.

I highly recommend this!