I want to use an Android Phone as a game controller on a game played on an Android Tablet.
What is the best connection type for me to use?
Because I read some information:
Bluetooth initial latency ~25-40ms
So, is it better to use Wifi or Wifi-Direct?
Just an example you can look to http://ardrone2.parrot.com/ardrone-2/altitude/ they are using Android/iOS device as controller which connects through Wifi and have a nice result.
In general I think wifi is a better choice, also looking into this comparison http://www.diffen.com/difference/Bluetooth_vs_Wifi