Having sailed both (but didn't own one) I can say that the Tartan will handle light air better, particularly upwind. The Tartan has more sail area/displacement and has a marginally slipperier hull
I doubt if you will have more room in the PSC. The canoe stern limits lazarette and aft cabin
Stability- Well a slight edge to the PSC. Probably a better limit of positive stability. But for coastal sailing, who cares.
The PSC handles fine under power. The fin keel
, rear skeg and big rudder
will handle well in tight quarters. The Tartan may back a little better due to not having a skeg.