I’ve got a Netatmo too 
That’s more to link in with the thermostat. It does seem to give realistic readings compared to other local stations, but I have seen some ridiculous values coming out of some. I suspect some are badly positioned and others may have the external temperature sensor indoors! So possibly not so much a problem with the devices and more about the users?
I guess that’s a ‘normal’ sized PC? I’m hoping to find something smaller, low-ish power and therefore possibly no-fan and silent (so maybe SSD). Anyway you’ve provided one marker in the sand - dual-core 2.4GHz, 4GB RAM and 300GB HDD. How low can I go?!?!