Dave55, I just don't subscribe to the "what if somebody down the road does..". The same guy who would indiscriminately move breakers around will probably replace a 20A with a 30A if his 4 plug-in heaters he's using to cure paint in his homemade autoshop paint booth keep tripping the 20A. I never ever fill a panel on a new install. My rule of thumb is to leave at least 8 spaces open in a 40 ct panel even if I have to set a 20 ct sub right next to it with empty pipes up and down out of it. I look at it from the viewpoint of "what if the next competent electrician needs to add a circuit and what if he's me?" If it's me I want it to be easy. If it's not me I want him/her to say "The original electrician was a saint!".
