I think I would primarily used the 12 inch as I don't personally find the screen space to 13 inches that significant an increase in size and I would find a benefit to having a 2 in 1 that utilises a stylus especially if it works well with Linux. I feel that form factor is better for travelling to and from work as well as on trains and planes.
I am not sure if I would keep the 13 inch and use it exclusively indoors or if I will sell it.
