My last trip in Shenzhen, I started using Didi more frequently instead of a taxi to go from my hotel to the office. It seems to me that the younger drivers tend to notice that I am using a foreign language version and use the Didi messaging to confirm the trip. The older drivers tend to call. I think the need to call is more out of habit or just being skeptical to confirm the pickup. At my hotel I was able to hand the phone over to staff if I got a call from the Didi driver. Anyway, none of this is scientific just purely anecdotal. Typical price for an express car is a few RMB more on short trips. Definitely cheaper on longer trips. My daily trip to the office is short, I could walk it but I don't want to suffer the flop sweat in the 95% humidity.