I understand you can't beat chinchillas in terms of cage odor. The female rats I used to have had no appreciable smell until it was close to time to clean the cage which worked out to be about once a week which was cleaned thoroughly and with bleach. I fed strictly an alfalfa pellet diet. It was clean enough that I had no problems keeping the cage on the same shelf as my clothing in my room.
Sugar gliders have protein (including gut loaded meal worms and crickets), and fruits and vegetables so their poo is odorous. They also have scent glands and constantly mark their territory. This requires you to clean all the accessories in the cage to keep the smell down. I know chins have scent glands too but I know the scent is rarely noticeable. I do understand gliders don't smell as bad as cats so I guess it's all a matter of perspective.
To get a feel for their size you can do an image search online. It seems like a typical adult is smaller than most pet rats and can be completely concealed in the palm of your hand. You have to get them as babies in order to bond when they can barely wrap themselves around your thumb. Adults weigh about 125g. A small pet rat weighs about 250g. I think it would be like trying to handle air. I'm not saying sugar gliders don't make good pets. They're just not my kind of pet.