Actually most of the data is not that far from my Davis VP2. Today, since midnight on the hour the difference in temperature has been within the range 0.18C and 0.46°C
The humidity tracks within 5-10% - showed 99% while we had a light rain during the night and only 89% on my Davis
The pressure tracked very close with most less than 1 hPa difference, and the biggest difference was 1014.90 hPa for Davis compared to 1016 hPa for BloomSky (the BloomSky table view does not show any decimals). Seems like BloomSky has made some significant improvements in this since I got my first device in February when the difference was much, much greater.
Still, only more of a good toy as data upload interval is anywhere from 5 minutes to 20 minutes or more and that is controlled by BloomSky.
Enjoy,
Paul