I've have/have had a lot of pets and these are the hardest pets I've had to take care of other than my horse. They are pretty stinky, but only their pee. If you keep up on cleaning the cage/pouches then there isn't much smell, the suggie itself doesn't smell bad, they stay pretty clean.
They're fun to have once you get a routine down with them, if you do a lot of research before hand it shouldn't be a problem!
If you do plan on looking into them these are a few points I think you should focus on: They need to live in pairs or more (unless you have 4 hours a day to devote to a single glider), they need to live in large cages (mine are in a really nice big birdcage, it was only $150), you will have to make their food (BML and HPW are some popular diets, I do HPW).
If you get serious about looking into them let me know, I'm part of a really great glider forum that has been a lot of help!