Either products are crappy quality at best.
The Sogou English search is extremely incompetent
Using Sogou English and searching for Android Studio, we only see 5 results returned by Sogou. At the end of the page, it states that the search technology is provided by Bing and Sogou.
In comparison, a search for Android Studio on Bing or Google returns 13 million search results. It's unfathomable that how such an incompetent product can be launched.
The Sogou English search is redundant to Bing
Bing is almost the only foreign search engine that is accessible in China. There is just no reason for users to choose a much inferior product when the original product is easily accessible.
The censorship of Sogou English is much overdone even by the Chinese standards
Searching Tiananmen on Sogou English returns no results at all because of Tiananmen square incident of 1989. Such a broad search censorship is unseen except in the most exceptional circumstances even in China.
In comparison, when searching tiananmen on Baidu, the No.1 search engine of China, general information about tiananmen is returned while information about the protest is censored. Same goes for Bing in China. This means that Sogou voluntarily goes beyond the mandate of censorship and even prevent its users of accessing much generic non-political information.