Sounds like you have a proxy smooth on your models. Even though it looks smooth in maya it's not. You need to do a real smooth on your models.
What a proxy smooth is, it shows you what the model will look like when you apply the accual smooth. It's a nice way to work so you can see what your doing but at the same time your not slowing down. Due to the extra polys you get when you really smooth your models. The thing is you have to remember to smooth your model at the end. Or you get what your getting in Keyshot or any other software you read that model in.
I hope I made sense. It gets very confussing sometimes.
Tim
