The issue I’ve had with Grab is the availability of cars. For local journeys within Sukhumvit area, I’ve waited 10-15 minutes for someone to accept my job but often have had to resort to the cowboy motor bike riders, whilst quicker and cheaper (with negotiation), are not exactly the safest. Uber was better in that you could pre book fixed price journeys to the airport. Could not do that with theGrab app