Style of Bad Guy Play/Mechanics

Hi everyone,

This is a pretty general question, but which do you like better of the following two choices for a game with miniatures, movement, and a board?

1) When the game controls the bad guys automatically or the game itself is what the players fight against - like Zombicide, etc.

or

2) When there's a player(s) controlling the bad guys - like War of the Ring?

What determines this? What situation makes one better than the other? Why do you feel this way?

Thank you!