The tornadoes in the original were much more ominous, yes - but the effects were way, way better, too. They looked real. Which made their strength much more scary.
The money-shot of the tornado taking out the barn behind the yellow Jeep truck is insane. It not only looks amazing, but it's memorable. I can't think of any shot in the new film that looked this real.
I liked Twisters a lot, though. But I do feel the tornadoes actually looked real and scary in the original. In this new one, it seemed like they tried to not show you the tornado.