I'm from the US but have lived in Thailand for the past year. I use Grab every day, often 2 times or more. 90% of the time, Grab is fantastic – quick, clean, ch

I'm from the US but have lived in Thailand for the past year. I use Grab every day, often 2 times or more. 90% of the time, Grab is fantastic – quick, clean, cheap. The other 10% of the time, the drivers either can't use a GPS, have a car that has issues, are drunk, tired, or just choose to drive recklessly. Overall I find the service indispensable, but quality control is an issue. During a recent couple of months in Vietnam, however, Grab was a mess. Drivers would regularly refuse to both pick me or cancel, and I was left stranded (if I canceled more than a couple of times, I would be blocked from using the service for a few days). I spent more than a couple of evenings sitting on the side of the road, playing a game of chicken with the driver on the other end of the service, seeing how many hours it would take them to cancel.