an't be specific about corn snakes, but we have a few reptiles as pets - DS has a carpet python, DD has a royal python, and we've got a boa constrictor and another carpet python as family pets.
Pros - low maintenance, cheap to feed, easy to keep, enjoy being held, don't need exercise, no expensive jabs from the vet, don't bring fleas in, fascinating for the kids, and MIL hates them and refuses to come in the house unless they're covered up 
Cons - equipment can be costly, food needs to be kept in freezer, and finding a friend to look after them for holidays can be difficult.
We've had snakes for a couple of years now after DS's hamster was eaten by the cat (long story, happened while we were away on holiday and the animals were in the care of a neighbour). DS decided he wanted something more interesting than a hamster, and a friend's daughter who was moving away to uni needed a good home for her python so we adopted him. DH then wanted a snake, so we ended up with another python, then acquired a large vivarium unit to fill an alcove in our hallway.
All the snakes are under lock and key, and we would not consider taking on a large animal like a burmese python which could be dangerous for the children, although the same argument could apply to a dog of course. Our boa's one of the small forms incidentally which will grow no larger than 5 feet.
So far the children have kept up the maintenance of their own pets - they change the water every day and help clean the vivariums when necessary.
The snakes are all used to human contact and are very tame - much more so than DS's hamster was. Although the cat's aware of the snakes - and often holds staring contests while sat in the hallway - she's shown no interest in them as prey and tends to keep her distance from them.
I've a friend who calls in every day to feed the cat and change the snakes' water, although he does not want to feed them. As they can go for several weeks without food this isn't a problem if we're away on holiday, but our local reptile shop can board the snakes for £2 a day each if needed.
In summary for us they're the perfect pet - easy and cheap to keep, tame, interesting for the adults and kids, and not much of a tie when we go away.