Sidewalk conditions/legalities can vary like the rider. Best not to make blanket statements concerning them.
Observer - The only true consideration is whether you are breaking the law. If not, common sense rules here. If the sidewalk is heavy with pedestrians, then you may want to go to the street rather than risk riding among so many pedestrians. Beyod this, put away your stats and enjoy your ride.
Shadowex - How would you interpret this section of the Florida Bike Law (section 316):
(14) Every bicycle shall be equipped with a brake or brakes which will enable its rider to stop the bicycle within 25 feet from a speed of 10 miles per hour on dry, level, clean pavement.
One LBS owner says it means that you can't go over 10 mph on the sidewalk. I think the 10 mph limit applies to the street too because it says pavement not sidewalk. Of course bikes can go faster than 10 mph but saying it explicitly in this section can imply that this is the speed limit for bikes. What do you think or anyone else familiar with this section?
BTW, my speed is increasing. I'm going at a super sonic speed of 6 mph on my trike. Yayyyyy!!!
