Some recent experiences using Google Maps and Baidu maps for public transportation in China (specifically Chengdu).

In general the routes that Google/Baidu output are correct, but where the stations are located are not. My method was to first use Baidu, write down where I was going and what bus routes to take, then confirm with google as I have google maps on my phone. I ended up spending quite a bit of time walking around just to find where the stations really where. In general, just follow the route towards your destination and you'll eventually find a station where your bus stops.

So in general the routes were mostly correct (regarding bus numbers), but stations were not. Surprisingly baidu and google agreed almost 99% of the time on stations and routes.

Reading Chinese helps a ton of course as most stations have the bus stops all in Chinese.