It seems to me the issue isn't whether a pilot is PIC in a regional, mainline, private, etc.... The issue is how well the pilot performs with the equipment she/he is flying. My friend is left seat 767 for a legacy carrier and I fly bugsmashers. He adapts to the requirements to fly his equipment; I adapt to mine. The results are the same: no metal bent, no hapless passengers or groundlings killed. It isn't the size of the plane, it's the skill of the pilot.