Product review (5 stars): Highly recommmended
I bought the two indoor and one outdoor kit, as well as the rain gauge and another 2 indoor sensors (I went a bit nuts).  And I love it.
Easy to set up, hasn't missed a beat.  The rain gauge is quite a way away from the hub, but still connects fine.  There's some differences between temp and humidity readings on the different gauges, but you can easily calibrate them to to be the same via the app.
One thing I was worried about before buying this kit was not having a display inside that you can refer to, which would mean you need to pull out your phone every time you wanted to see what temperature it is. However with each gauge having this info, it's easy....if  I am in the lounge room I can see what the temp is. It's only if I want to see another location that I need the app, but that is no big thing.
The gauges are very easy to read, and also look nice; modern and not old fashioned.  Battery life seems excellent as well.
Highly recommended