Is Beijing the biggest tech hub in China? Silicon Valley is really a long corridor of tech between two cities, SF and San Jose. Is there something similar in China? Would you say that China has multiple tech hot spots or is Beijing it? Is Beijing more like New York in this respect? Do you see what I'm driving at?
Beijing is absolutely the counterpart of Silicon Valley in China with similar area and much bigger population. Although two of big old three (Baidu, Alibaba, and Tencent) is located outside of Beijing, most Internet companies especially new stars such as Didi, Meituan-Dianping, Xiaomi are all here.
Beijing is most certainly the software center of China. I work in a Shanghai startup and when we raise funding we have to go to Beijing to find the VCs. Beijing also has the best universities in China, so the talent is there. China's version of the Paypal Mafia is more like the Microsoft Mafia. Look inside of most top software companies in China and you can almost certainly find a handful of execs who worked at Microsoft around the year 2000. Microsoft's offices were (are?) in Beijing, so most of them hung around after they left to startup or join other tech companies.
Shenzhen is the center of the manufacturing world, and as the article points out they have DJI which produces 70% of the world's drones. Essentially anyone who wants to produce something cheaply and quickly will have something being produced in or around Shenzhen. If the Internet of Things really takes off into a mainstream industry then Guangzhou and Shenzhen will become a secondary hub of innovation. I just heard recently that Cal-Berkeley is establishing an engineering graduate program with Tsinghua to be hosted in Shenzhen. For a university right outside of Silicon Valley to do this is definitely saying something.
Shanghai has a decent number of finance related startups, but people in Shanghai tend to be motivated to work in large multi-national companies. Go to a startup in Shanghai and you'll find mostly people from outside of Shanghai without the best education - not saying that it's impossible for these people to create a great company, but it's a far cry from Beijing where Tsinghua and Beijing University students are being recruited to early stage startups.
Alibaba and a few other tech companies are in Hangzhou, but that city still lacks the pre-A, A series type companies that Beijing and Shanghai have.
Chengdu in the West has offices for half of the Fortune 500, but although I've heard the local government is pushing hard to attract entrepreneurs, their startup ecosystem seems to still be lacking. It's possible that if some of these employees leave their Fortune 500 employers to startup then the city could become more of a hub in the future.
Beijing is more like the DC area, but even then the comparison is flimsy. As a long time Beijing resident, I would say Shenzhen and Shanghai have more to offer. Beijing's importance is mostly driven by the government.
Beijing's importance is not driven mainly by the government (although open-mindedness of the government definitely contributed to this), but by the ecosystem: best universities (Peking University and Tsinghua University among dozens of others) and best research institutions (the Chinese Academy of Sciences and research centers of big companies), most big VCs, IT communities/media, and most important, entrepreneurs.
In Beijing, if you have time, you can attend some interesting IT meetup everyday. It is what you can not see in Shanghai or Shenzhen.
Talk to somebody in Shanghai or Shenzhen startup community. You will have the insights.