I've been following Michael Pettis quite closely. Great analyst, understands and explains the global balance of payments very well, lives in China, etc. His opinion has moved from 'China needs to rebalance' to wording that sounds like he's not sure there is going to be much growth for a long time.
China's growth for some time has been the result of malinvestment on a massive scale. At minimum since 2008, possibly even before that. The factories that we think could be productive and producing things people really want at the right price could be in that position because of very negative inputs (unaccounted for pollution, interest rates being subsidized by someone else, etc.) Fundamentally, when you have an economy growing at a rate above the interest rate, many companies can just overgrow their debt while taking on new debt. Unprofitable operations can be hidden for decades.
It is now within the realm of possibility that China could see 1-2% growth for decades ahead. In short term, I would expect negative GDP growth. Based on what has happened to the price of oil (and other raw materials), and the drop in high end consumption due to a 'corruption crackdown' this could already be underway.
In general this should be a good thing. Certainly it is for the environment and climate change.