Re: Everglades Rat Snakes.
I know this is a month old, but I'll give my $.02.
The "other" ratsnakes (i.e. Elaphe obsoleta sp....which includes the blacks, greys, yellows, and everglades) are really not much harder as far as I can tell than corns. The main difference is size; corns rarely exceed 5 ft, whereas the rest can commonly get 6-7 ft.
I do know a few folks who keep them, and from what they say, part of the matter is that there is a lot of legality issues regarding the black rat snake (E. o. obsoleta). Many states in its range prohibit its collection as well as shipping it out of state.
Another thing is bloodlines. Many E. obsoleta enthusiasts like to be "purists" and there is lot of intergrades happening with the species. Since the black rats are the species type and the others are sub-species, this causes issues with the legality of the blacks I mentioned above.
As far as Everglades go, Ive never worked with them myself but I do know they require a tad higher humidity than the rest.
Overall, I honestly don't think they're much more diffcult than a BP or a corn, etc. I say go for it if you really want one.