[DustyPorViva]

I just checked them out, and here's my opinions.
I agree, there doesn't need to be effects on EVERY terrain. Sure, haunted houses should kick up dust, but not other interiors... perhaps houses. Dirt kick-up should be brown, not black.
As for grass, while it does look good, grass doesn't kick up puffs of green. I'd say it'd look much, much better if it kicked up blades of grass behind you.