You need to have contact number. tbh, uber is cheaper most of the case for long distance journey. So you should have over 90% chance to take uber from airport to downtown. you need to specify terminal and door number in uber. if CX, it should be T1 and you can choose door 1 which is the closest. You will meet the car in the arrival pickup point (there is clear sign to direct you)
In detail,
Grab - you can "grab" private car which is similar to uber but with flat rate
- you can choose to "grab" taxi as well which may charge you few dollar fee like other taxi apps
Uber - now they may give you flat rate or flexi rate.
I use both apps to compare Taxi fare, Grab Car rate and Uber rate, then pick the cheaper one.
You can buy sim card in SG airport which offer data and phone service. Think it is around S$20 - S$30. you do not need to buy data only card.
Yes, you can sweep to take 6 seater but of coz more expensive. Below is the example of taxi in grab, grab car, grab six seater, uber car, uber 6 seater. The one of uber with 9.19 is uber pool that's group different passenger together to share same car.
Can pay by cash in grab. For uber, it used to accept credit card only but i heard my friend that they change to accept credit card (i am not sure if it is true).
oh, yea. you will be charged additional fee if you pay by credit in taxi which is not the case for Grab Car and Uber.
Also, you can input the postal code in the apps/google map when you book the car. So you can avoid to be confused with different place with similar name.