He definitely has the energy of someone quite a bit younger... maybe in their mid 60's. I too wish he'd lose that chubbiness. It would do his heart a good service. His face has become so bloated recently, it's just sad.
Nimoy is looking more frail. And he's obviously taking it quite a bit easier than the Shat. I don't blame him... At that age I'd be lounging by my pool with a nice cold drink tapping away on my iPad rather than globe trotting.