I'm really unconvinced by Xi Jinping concentrating power. It does look like he desperately wants to be China's Putin (with the charisma of Medvedev), and there's nobody to stop him.
Yeah, that's probably a bad sign. That said, I don't think it's as fundamental a difference as a western perspective makes it out to be. Westerners are, for obvious reasons, terrified of charismatic leaders - but there are plenty of dictatorships that get along just fine with a bureacracy. Having an official great leader doesn't necessarily transform the power structure.