I did a quick test of the new hardware and mobile App (iOS) Set up to trigger my Nikon D800 to fire when sound is picked up by the handset.
Using the camera shutter actuation rather than flashguns is not going to result in as snappy a response time, but with care you can capture the immediate aftermath of a balloon burst (in this case filled with flour)
I fired a nerf dart (with a pin in the front) at the balloon from around 5 feet away. The time taken for the sound to reach the phone and for the phone to trigger the D800 and for the shot to be taken equates to around the time it takes for the dart to travel to the target.
The new hardware paired with the updated iOS App feels more reliable than the previous incarnation (which already worked great) it is also a little snappier to trigger (make sure that you set the correct values for delay in the settings menu...
I'd like to see an option for the trigger to fire the camera (or Flashes) on a numbered trigger count. e.g. fire the camera on the 2nd noise detected above x value. This would help avoid 'false' triggers for example when opening the shutter before a burst
Example photo attached with the two states of the flour balloon..