I think it's easier from the top. Even if the car is up high enough, you would still have to remove the center tunnel, in order to maneuver the trans back from the engine enough to disengage it, and lower it down through the bottom. Plus, the rear end of the motor needs to be supported, either way.
I just took mine out two days ago. The experience is fresh in my mind. Out through the top works well -- and, IMO, would be no harder than out through the bottom.