I have been monitoring it and it will do heavy drive reads like 35%, heavy CPU and sometimes heavy RAM every 15-20 minutes for different things. The services responsible for this are system services (including System), Cortana, Windows Update (when it's checking), the stupid new memory compression system (which I think is mainly to blame for all this) and updating Apps and live tiles.
I already turned everything I could off like update P2P sharing, feedback data, auto updates etc etc.
MS Edge also is a dog, any flash based stuff and it will freak out, also with just a few tabs open it uses way to much memory, no wonder its a working progress. Just idle it's using 10% of my CPU!
My laptops fan never goes to the lowest level, its always at the 2nd. This is a fresh Win 10 upgrade on top of a fresh Win 7 install with all updates applied. There is nothing 3rd party on it. It could be that because the OS has just been installed it's doing lots of stuff and will eventually settle in a few days but so far I'm not impressed.