I once read they (or this might have been only for guinea pigs) should be off the ground since they could get stressed out by the sound and vibration of people walking around:roll:
The school cages are off the ground but that is mostly to ease cleaning, so we just dig out the sawdust and let it fall into a box underneath, but with a regular pet shop cage this wouldn't be possible anyway so that's pretty useless:roll:
Plenty of rabbits like to sit tall, maybe to get a good view of their surroundings, but its better to just give them a taller cage or a box to sit on, instead of putting their cage way up high so they can't get out on their own.
As for guinea pigs and being stressed, all the school's pigs are in pens on the floor:roll: Never once had one get stressed because of people (or stomping rabbits) walking around them:lol: (and no the buns are not in with the guinea pigs, but they sometimes get the run of the room, and then they pass the guinea pig pens sometimes.