Hi, personally I would give it an hour from landing. If you book a transfer they will monitor the flight and wait for you anyway. We have always grabbed taxis before, but they no longer do the flat rate and it cost us a fortune. We found that with all the taxis in Miami this year. We’ve also had some journeys in taxis that have been quite hair raising and we’ve had a few near misses!!! Other people may have different opinions but for me, I will be booking a transfer / driver in future. Have a look at Viator as well, they do some good deals on transfers. Hope that helps.