I'm that player who always DMs because their friends aren't capable of doing it due to whatever reasons. I enjoy the worldbuilding aspect of DMing but when it comes to RPing I much prefer the personal interactions my character has with the world instead of controlling an endless string of NPCs.
I enjoy creating highly optimized combat encounters but hate running them. I've grown from a mechanical min.maxer to somebody who fits and matches the mechanics to their character story. The goal now is for the mechanics to give form to the personality and story of my characters.
The same goes for my DM style. I have created many homebrew rules and incorporated even more from others. I regularly use the Witchdusk campaign setting with my own alterations. While I use published material it all exists in a world of my own making. I am willing to go as far as creating an entirely new base or prestige class for a player who desires it but is also willing to work for it.