I have always used them even in Bali. I have been told that Indoneisai is so unsafe (but I think Bali is an exception). Now I wouldn't use one in Jakarta.
Anyways the Hk taxi is just BS. They still don't offer Amex. Anyways I'm glad that they invest in HK. I especially like their 7 seaters I'm sick of finding two taxis if I've 5/ 6 passengers. If uber allows pre booking service like taxis in Singappe then it would be perfect.
i have had one trip in Hk where it took the driver an hour to get to Fortreshill from central, Uber kindly offered me a free trip after I logged my compliant.