Prof. Garfield is a regular around here and an occasional GOTM player. He is very knowledgeable and a top rank player.
Watching the videos is interesting even though it is rather time consuming. While I still think the best way to learn is by doing it: play, take notes, discuss, and compare with how others do it as we do in GOTMs, videos reveal aspects you do not easily see from snapshot stats like actual city placements.