We used them in larger 36"+ tall enclosures for Gargoyle Geckos with success. Humidity is 65-75%, so only a little drier than a PDF vivarium would be. Even with higher humidity, they seem to do just fine. There are mini ZZ plants available, but even then they get pretty large.
The plant has doubled (now touching the top) after about 6-7 months of growth. It's doing well, even with the smaller amount of light they are getting. They do get 36" high or so. (some say even larger)
I grow a differnet clone of Zamioculcas zamiifolia I got from Arid Lands Greenhouses in Tucson, and its a fairly slow grower. I can't see either clone working well in anything but the use MeiKVR6 said. I don't think they would like the high humidity of a PDF tank as they are from a fairly arid area in Africa and they've adapted to the climate in the way they can go dormant to the waterholding leaf bases. Very easy to propagate from leaflet cuttings, much like some other aroids, such as Gonatopus and Amorphophallus / Pseudodractontium.
Cheers guys. I know how big they get, size doesnt bother me, can always be moved when they outgrow the viv but as you guys have confirmed, the conditions in the viv probably would just lead to a rotted plant.