I like the 433. I have considered it for the snake species I keep. I have heard stories of them warping and sagging, but I suspect most this is from improper use. A friend of mine purchased several used Visions. Most were warped and the doors did not function well.
We put the base layer of some of the smaller Visions on some racks that were shimmed to form a flat surface across the room. The 433 set on top of all the cages.
We also used silicone spray to lube the tracks. I have not been back but my friend says the 433 works great now. He loves the cage. He also says the doors on the small cages work fine after setting on a flat surface. He's since moved so I hope he sets them up the same.
What really impressed me was how well the cage looked after housing a trio of Corucia zebrata for years. They can do some serious damage with their claws but the cage and glass were fine. I was also very impressed by the strength to weight ratio.
But don't be afraid of building your own cage. You won't match the strength, weight and durability of the 433, but there might be design features you want and can only get from building your own.
I recommend DIY as a way of getting design features you want, not for the cost savings which tend to not be that great. If strength to weight ratio were important, the larger Visions would be tough to pass up, especially for a species that needs a lot of direct moisture and scratches a lot.
I'm not sure if I have seen the larger Vision you mentioned.
