We use ours all the time when driving from place to place and we stop for lunch at rest stops. The only concern I have heard of is to not step on the edge of the slideout floor as it is raised and could crack/break the underlayment.
If useing the slide out when in bothers you , you can cut a board at the same angle as the lip on the slide and you will be solid to the floor. I believe this id what the farmer does. It was wrote up here a while ago.