BT Buffer
I have an iPad, iPhone 3G, iPod Touch, and a Sprint/HTC EVO all as options for my radio. I would say that the delays seem to be heavily on the end of the device, and not so much on the Radio. Also, it is important to note that only since 4.2 of Apple's iOS, have they used the correct BT Profile that enables the "Tech Package" radio with BT to use the radio and wheel controls to advance and go back tracks.