I know this is an older post, but I thought I'd chime in.
In all honesty, I would not house Cynops orientalis (or any other aquatic caudate) in such an enclosure, unless it was an eft in its brief terrestrial stage.
At one cubic foot, this terrarium translates out to approximately 7.5 US gallons. In the manner that Exo-Terras are constructed (due to the doors,) only 1/3 of that volume could be filled with water, giving a total possible swimming volume of only 2.5 gallons. With pebbles and filters along with other miscellaneous decorations to occupy further space in that setup, only maybe 2 gallons would be available for any aquatic newt to swim in. This is rather quite limiting to animals that would only rarely leave the water.
I agree, though, that it could work for small, sedentary, terrestrial amphibians quite well (as stated by several posters above.)
An additional problem with the setup is that the Exo-Terra hoods are varitable heat traps, as they have horrid ventilation and constructed for use with halogen or spiral compact bulbs. I fear that the use of one would heat a terrarium to temperatures not well tolerated by any temperate caudate.
Considering the price of Exo-Terra products, too, one might conclude that purchasing such an expensive (and small) product might not really be worth for use with any species of newt or salamander, as they'd be much better off if you instead spent that same amount of money to purchase a much larger aquarium. In brief, you'd be paying much more for a smaller, less comfortable setup for your inhabitant.
Granted, the aesthetics of the enclosure must always be considered, and the Exo-Terras are certainly attractive. I understand that we often subject our captive animals to less than perfect conditions for the sake of simply being able to own them, and am, myself, guilty of such transgressions. My argument is that, quite simply, for the amount of money one would spend on such a setup, you could purchase a much better enclosure that would keep your animals happier and give you greater options.
As for keeping Dendrobatids in it, I would not even keep thumbnails in anything less than 10 to 15 gallons, with at least 20g for larger species. They're quite active, and not well suited for small enclosures.