I have based my cage choices on the snakes I keep in them. I keep my largest snakes, Chinese Beauties, in cages with sliding glass or acrylic doors. The reason is that I can open the doors just a little to spot clean, change the water, feed, etc., without the snakes leaping out of the cage - which is what I fear would happen with drop down style doors. I don't want a snake falling six or seven feet to the floor, from a cage stack. I have Vision, Animal Plastics and Rich Beasley cages.
The Visions are nice and roomy, and have a smoothe, easy to clean surface, but also have some oddities like a sort of lip around the door which is sort of difficult to clean around - and which snakes can hide in (might be a consideration for keeping hots). One of the best things about Visions is that they are pre-assembled.
The Animal Plastics cages are the nicest, most professional looking cages I have IMHO - and are a very good product. The type of PVC they are made of is not as easy to clean as other types of plastic, though - although with enough soap, bleach, and scrubbing they will come clean. You have to assemble AP cages, but they are very precisely cut, and easy to put together.
Rich Beasley sells some very affordable cage kits, which are very similar material to what Animal plastics uses. The drawbacks to the cage kits are cosmetic, and they look like DIY cages: Everything is straight cut, so the panels fit together butt-jointed, as opposed to dadoed like AP cages. The panels are not pre-drilled, and you have to supply the screws, and sealant. Also, the door track is tan, which does not match either the white or black cage material. However, the finished product seems sturdy enough, and is comparable to AP cages in weight, and does the job at much less cost than AP.
There are some cages on the market that I would really like to try, but due to the fact that they don't make sliding door cages, I won't be buying any. The Pro-Line cages made of HDPE by Constrictors Northwest look like they are very easy to clean, are supposedly about as strong a cage as you can get, and I like the fact that light shines through them. If only they made sliding door cages...
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-Toby Brock
Southwestern Center for Herpetological Research