There's room for both. I think the pacing and length of the Defunctland videos makes them more appealing to the casual fan. I'm very grateful for Martin's videos and enjoy them a lot, but only a super fan would be interested in extended footage from rides they may have never experienced.
Expedition Theme Park is better with that pacing and surface level interesting and Defunctland is a bit PETA about Sea World.
Martin, GP to Enthusiast, Season Pass and Martin's are great.