I sent you an e-mail with probably too much info.
To answer your questions in case others are curious, they are definite lead dogs. They're instintive hunters (used for boar) and will take off after "prey" and ignore anything and everything.
They're not real hyper that I can tell. They tend to read their companion and go with the flow. Ours does the Indy 500 through the living room sometimes, but we love it and it's good excercise for her.
Like I said in my e-mail, they're highly intelligent and are born problem solvers. We got the Shiba Inu as a compromise. I wanted the Akita but the wife didn't want such a large dog. The Shiba Inu was a given at that point.
Another dog I don't know much about but found interesting was a
Canaan Dog
They supposedly make good watch dogs and are family oriented. I think they bark a lot though. Since it's a "herding" animal, your apartment probably isn't big enough. If you click on the video in the link, you'll see they very agile and resemble a Shiba in the head.