The first GP we went to was way overbooked by who-ever did the booking. I loved him, though, we the waits were usually worth while.
Now with the "new systems" in place - we usually don't have to wait very long in the office. If the wait gets to be over 15 minutes from the appointment time, I will go to the desk and inquire how things are going.
"Stuff" happens in clinics, too. I usually plan on more time than "necessary"