Hey TST,
Let me start off by saying one thing I'm a BIG guy close to 350 lbs. I thoroughly enjoy walking the course for multiple reasons.
The first is cost, at roughly $15 per 9 hole round or about $850 a year for unlimited rental. That alone is a huge added expense.
Second is the frame of mind I stay in during a round when walking. I find it easier to blow off the steam from a bad shot. Riding in a cart always seems to be darting through the course looking for a ball and swinging at it for me. Very quick but sometimes not thoroughly thought out.
The third