These coaches are fairly complex machines.....like a house that goes 70 mph. I agree with Gary, take the time to thoroughly check them out, item by item. Do it in a safe location where you have time to understand how each system works. Otherwise, you may find yourself trying to figure it out in an unsafe location, like a busy intersection or freeway, or some other place where it is difficult to get help. Best to learn as much as you can during a pre-purchase environment. There will still be surprises you did not prepare for or understand.
As you learn more about your coach, there is nothing more enjoyable than owning a Prevost coach, and meeting the great members of POG.
Best of luck!