New appointments are always kept to the arranged time. Personally in my experience as long as you communicate and show courtesy, time is non rushed and usually doesn't start until the chit-chat has passed.
Can you give me list of SP's that you see?

I would love to have another 15 minutes added to my hour.
I am not suggesting that they all rush you, but there are tactful ways of saying things after the storm has passed, "ohhh you are hot .. i think you should take shower (and get out of here).... OR .... would you like to take a shower before you leave?" ..... and of course there are a few more. May be we should start a thread about "When Do You Know Your Appointment Is Over" or "Things SP's do to hint that you should get dressed and leave because your time is up."
There was just one time, where I ended up staying about 20 minutes over the hour but then I was he last appointment of the day.
Time is money to the ladies and we should respect that.