My own family were great when they came. They do not expect to be waited on and we all have the same habits. We even rented a small 2 bedroom cottage with my parents and kids (they were 18 months and almost 4) many years ago and my grandparents couldn't understand why we weren't fighting! It's the same when my kids come. However, when DH's parents came (twice, in all of our marriage), they expected to be waited on hand and foot.
My house is big enough now that everyone can have space, but we don't have many guests.