My parents let all three of our little dogs sleep with them at night. Since they are small they do not take up much of the bed and they never have any problems with pee on the bed or making noise at night. Our larger dog sleeps on the floor or the couch.
Since my parents' bed is so tall the little dogs have trouble getting on or off, so I suppose that avoids them jumping off and on whenever they want to. My parents also don't force the dogs to sleep with them, the dogs like sleeping together on the bed. The three of them tend to huddle on near the end of the bed by my parents' feet.
The only complaint about this that I have heard is when one of the dogs starts to snore, but it doesn't happen very often.
