Animal Plastics cages are the new standard, and I plan to soon redo my snake room exclusively with their cages and racks. To address the ventilation question, AP cages are vented in the back. The screened holes on top are just an extra option.
Visons suffer from a few fatal flaws, IMO. The first is the ledge above the door on some (all?) of their enclosures. This isn't too big of a deal with corns, as the worst that will happen is you'll panic when you can't find your snake. For my use, however, this design flaw is completely unacceptable.
The light shroud in Visions is another poorly designed concept for those of us who stack cages. If a light burns out in the bottom cage, the entire stack needs to be unstacked just to change the one bulb.
For corns and the smaller cages, this wouldn't be an issue, but a common complaint with the larger Visions is that they tend to bow when stacked. This makes sliding the door open or shut all but impossible. Sometimes they'll sag under only just their own weight.
Visions also do a very poor job of retaining heat, and forget about maintaining humidity...you'll be misting often.
Also, if you get a Vision, you may want to invest in a putty knife to scrape urates off the plastic. It's been my experience that urates stick tenaciously to both Vision and Neodesha cages. AP, Boaphile, etc, don't have this problem.
In short, I like the look of Visions, but that's about the extent of it. For me, they lack some of the functionality that I'd expect when paying top dollar for an enclosure. For merely looking at, Visions are nice. For actually housing anything, an aquarium with a screen top is cheaper and more functional.
All in all, I'd choose AP over Vision any day of the week. Vision has a place in history as being one of the first large cages on the market, but the design is severely lacking.
