The temperature are ultra precise, just make sure you think about the appliance in a good place and updated display of the weather is just as accurate (that night, snow on 32 departments, myself included, it snowed during the night, the unit me clear the snow logo, then the time will be rain, bingo, the device is updated on rain)
I think the bad reviews (the temperature level of precision), coming probably nobody who install the device in the wrong place. Last detail, my car tells me 0 ° C to 6 am for the outdoor temperature, the thermometer at home it clear -0.4 ° C.
Now to see on battery consumption, however I am disappointed in any way. The instruction is in French and the external probe has a support. Finally the unit is supplied with all batteries.