I'm currently using these cages for my Carpet Chameleons and I think they are great! They were super easy to put together and are lightweight should I need to move them. The ventilation is good, they have a sturdy, thick screen top (lights don't bend the screen) and holes drilled into the top half on three sides of the cage. They hold the humidity well. My chameleons are not stressed by the clear walls.
The only drawback I have would be the drainage issues. Eventually, when I have a bit of spare money, I'd like to plant the cages and have them more automated than I have now. For the amount of water I need to keep my guys hydrated and the humidity up is small so spot cleaning isn't too bad.
I'm not sure I would use these cages for Panthers and Veileds that are quite active and need more room but for the small and mid sized species they are wonderful.