Hi,
This is not a very serious issue, but rather a small small annoyance:
3D Coat on Steam does not show the time spent using it.
For me it always shows "0.0 hrs on record".
Others have the same problem too:
http://steamcommunity.com/app/100980/discussions/0/648814845633449132/
http://steamcommunity.com/app/100980/discussions/0/360670708787560538/
Thanks!