I like interactive because when you are switching cars at sidings you get different weights in the cars. Thus, In theory, driving should be different based on the weight of the train. There are few industries that need an animation. I do like the Multi-Industry ( forgotten the name but philskene uses them ) where you set out cars and they load or unload while your doing other things. In real life most engines don't sit around while a car is loaded or unloaded.