WT5A wireless transmitter issues

Anybody have data transfer issues with the D4 and the WT5a wireless transmitter to an IPhone? Sometimes it works incredibly fast and other times it can take minutes to transfer one photo from the camera to my IPhone. The distance from camera to phone is less than 30 centimetres.
Also, the connection from the Iphone and the camera using HTTP is a direct connection right, camera and transmitter direct to phone?

Same here, with the model that's for the D600. It works well sometimes and not very well, other times. It sort of reminds me of cellular technology. It works, then it doesn't. I think that some areas of "wireless" technology, are still in the juvenile stages. They will probably get better over time. Remember the early bluetooth devices?