citro wrote:
Built-in flashes have the known limitation of overheating and recycling times. Therefore, my opinion is that, when it comes to sustained shooting, the Integrated Speedlite Transmitter on 7D has some serious drawbacks compared to the classic ST-E2.
Of course, I might be wrong. Here is the question: how is the Flash Commander on Nikon bodies behaving in similar conditions?
However, to act as a master it merely has to emit patterned pulses at very low power. It's not nearly demanding as normal flash operation.