At 7.5 months, I am surprised that Kacee is so mellow. Funny timing for your thread, because I have been thinking about this lately. Muffin was much more active and ornery than Kacee. Muffin was my little imp!
I don't know exactly how to categorize Kacee yet. She loves long walks and jogging. She loves to hang out in her yard. She can play with her squeaky ball and other squeaky toys for the longest time and yet she is so very mellow the rest of the time that she seems much older to me than she really is. She's perfectly healthy, too. They can be as different as day and night.