Product review (5 stars): this thing is great. My sensor and display are probably 60 feet ...
This thing works very well.

I set the sensor and the display next to each other in the same room for a while, and they show slightly different readings for both temp and humidity (not more than a few degrees or % humidity).  If you don't need 100% accuracy, this thing is great.  My sensor and display are probably 60 feet apart and through several walls and I have had not had any issues with signal strength.  This is a good product.