You might. Latency is never zero with Bluetooth and for AirFly, it is generally 30 milliseconds or so, which should not be discernable while watching a movie or listening to music. However, if the 3.5mm audio jack on the source device is a bit overpowered, it can cause longer (noticeable) latency. This is most common in devices such as musical equipment (amps, electric guitars, et cetera), but can happen with any audio port.
