After a couple of decades away from RPGs, I've have been a player for several months with a steady group playing FantasyCraft. Meanwhile, I've been preparing a campaign of my own and done a lot of system-agnostic research, note taking, and world preparation. All high level stuff for the beginning, middle, and end of the story I intend to create with the players. I intend to fill in a lot of the spaces between with pre-gen adventures I have in mind.
Now I have to decide on implementing the setting using FantasyCraft mechanics or Pathfinder mechanics.
FC comes with familiarity, but I'll have to do conversion of existing material I want to use. That could be a lot of work. The one thing I've not done in FC is conversion (being a player).
Using Pathfinder I get the material for free, but may have to do some house-rulings for things I've heard are broken but seem improved in FC. Also, I'll need to figure out what supplemental stuff to include/exclude. Wrt Pathfinder, I've been listening to podcasts, read a good bit of the core rulebook, looked through some third party material, and have been reading about it so I know something of the game, just no practical play experience.
So, given the choice, would you opt for game mechanics you are more familiar with or for which there is more material?