I know a guy who has an F3 Savannah (I know him through the net so I've never met the cat in person).
The cat is gorgeous and apparently fun to be around. Very energetic and active, the guy also has a small dog and him and the cat get along great and play fight a fair bit.
I know he can't let the cat have free range of the house unsupervised because the cat gets destructive when bored so whenever the cat is left alone it's closed off in the 'cat room' which is filled with cat toys and cat trees and a window to look out of etc.
He's also said that he doesn't think he could handle having two Savannahs (when someone asked if a second cat was planned).
Personally I'd stay away from the F1 and F2s I think they're too much feline for most people to handle. F3s and onwards I think is probably manageable but you have to do research first and decide if you're prepared to live with a very high energy feline that will ruin your chances of having a tidy and polished home. Which is what you're doing now so that's great
As for the wild cat blood in current cat breeds etc, I have a bengal so that pretty much sais where I stand in the matter.