I like them a lot but don't put small corn snakes in them. My yearling figured out how to squeeze between the glass doors and get out! I caught her twice almost half way out of the cage.
To stop this, I bought some wooden dowels and forced them into the track to block the vertical gap between the two glass doors. The second time she tried to escape, my "troublemaker" pushed one of the dowels out of the way. I heard a "ping" and was able to catch her before she got out.
I have one cage with one vertical dowel and a second that lies horizontally. (She hasn't beat that one yet!)
Corn snakes are the greatest escape artists!
(Oh, I also drilled two small drain holes in back of the cage to make the cages easier to clean.)