These hybrids do not act like any domestic cat. They are highly active and social. Far more than a domestic cat. You can leave your house for the weekend and most cats won't miss you. They will get along just fine without you provided they have food and water. A Savannah will grow bored and upset and destructive. Also due to their size, they are more likely to do a lot more damage to humans or animals should they get aggressive in play or attack. So far I have not seen any reports of a Savannah attack, but that doesn't mean they don't happen. People don't always get treated by a hospital for an injury their pet inflicts and owners are not gonna report to the ACO or news when their cat kills one of their own pets.
I urge anyone looking to buy one of these hybrids to look at the cons as well. And be sure to spay/neuter the animal, if the breeder hasn't already had that done for you. Spaying/neutering can help curb some unwanted behaviors and make having one more livable. But at the end of the day, if someone wanted to either get a tiger cub or a Savannah cat, and there was no talking them out of it, I would at least try to talk them into getting a Savannah.
Reading through that site, a lot of the Savannahs were neglected and treated poorly. I have spent some time talking to respondsible Savannah owners and they don't report those same problems, aggression wise. There are some problems with litter box issues. Some do prefer their own private large litter box, but they aren't urinating all over their house.
Declawing....that will make a LOT of cats aggressive, including domestic cats. When I worked in grooming shops and the vet office I got ready to fight tigers when people brought their declawed cats in. Cats who get declawed often become more aggressive because they have to. They lost their first line of defense. It would be like taking heavy duty scissors and cutting off all the hedgehog's spines. They are gonna use their second line of defense more to protect themselves, their teeth. Now any wound from a cat is more susceptible to infection from a dog, be it scratch or bite. But bites from cats are especially dangerous. One of my groomer friends twice got blood poisoning because of cat bites....both times the cats were declawed. You will see the same aggression in wild and hybrid cats that get declawed. If someone wants to declaw a Savannah they are getting, then they have no business having it. They are trying to take shortcuts and don't understand cat behavior and physiology whatsoever, they are setting their cat up to being abandoned or euthanized.
At the end of the day, domestic is the best answer. Millions of cats are euthanized every single day because there are not enough homes. Every time someone buys a kitten of any breed, a cat will die at the shelter.