. . . I have a TON of critters, and need to house them efficiently and economically - (just received my Underwood today!!) You are right - those glass-fronted cages are super - but this was an experiment, to see how I like it. And it works - it's inexpensive - easy to clean and most of all - Bailey the Cresty seems happy (of course, how can you really tell with that stupid grin on their face all the time. LOL!) . That fits the bill for me.