Not one I have tested, but this is cut from their spec.
So, what is it not?
We expect most SteamOS users to get SteamOS preinstalled on a Steam Machine. Although we have made SteamOS freely available for anybody to install, the installation experience is not intended for a non-technical user.
Most importantly, SteamOS only supports a certain set of hardware (you can read more in our
FAQ). We will add support for newer hardware over time, but we have no plans to add more support for older hardware.
Users should not consider SteamOS as a replacement for their desktop operating system. SteamOS is being designed and optimized for the living room experience.
ADDENDUM
If you want a user-friendly medium weight distribution then you have a great choice including, Lubuntu, Peppermint, MX-21, Experian, Endeavour, Linux-Lite, Parrot home edition, to name just a few.
My best advice is to download say 6 different distributions, and run them live from the pen-drive to see which works best on your box, and which you like the look and feel of the best, Because at the end of the day it's Linux, so it is your freedom to choose