A few months ago, I ordered several racks from Vision Herpetological. These cages have a genius design...period. They were designed with ardent creativity to maximize the efficiency and minimize cost of the set up...and Vision executed their "vision" without cutting any corners on quality whatsoever. Heating is simple. Ventilation is simple. The entire rack is light and easy to maneuver. A new rack can be assembled within minutes straight out of the box. My wife even assembled one in about 25 mins. :)
On the larger adult racks like the CB70s, there is about a 3/4 cm space (rough estimate) between the top of the tub and the ceiling panel. This leaves plenty of space for ventilation around the entire rim of the tub, and each ceiling panel is perforated. Judging by the rapidity by which the water bowls evaporate in these set ups, Vision racks seem adequately ventilated for Trans-Pecos Ratsnakes. If desired, Scott at Vision can actually custom-tailor the racks (for ventilation-needy species such as subocs) to leave an even wider gap between the tubs' rims and each ceiling panel.
Now heating a Vision rack takes the cake. Each ceiling/floor panel has grooves manufactured into the topside of each panel, where you can fit a desired length of Zoo Med Heat Cable. You can use as much or as little heat cable per level as desired. And here's the kicker...you only need one Zoo Med Heat Cable to heat an entire rack. No more heat tape. No more costly heat panels per level.
Now if Zoo Med came up with a Heat Cable that had a built-in rheostat like some of their heat pads, then I would consider these cables perfect.
All racks come with casters for wheel maneuvering, and they also come with a heat cable. Side guides snap into place easy and enable the tubs to glide in and out easily without any turning. And each rack can fit through a doorway.
The bottom line is that these racks are simply a joy to assemble and to use. We keep our hatchling subocs in Vision Table Top Hatchling racks, our 2 year olds in 32 quart Vision racks, and our adults over 3 years of age in CB70 racks. If you keep and/or breed subocs, we advise you to do the same.