I believe there is small disadvantage to running freqs concurrently on a GB4000. The power is distributed equally over the freqs. Here is an example that utilizes the 10W RF amplifier unit. If you run 4 freqs concurrently, the 10 wats is distributed equally across all 4 freqs. Each freq gets 2.5 watts. This is my understanding in talking to the technology owner and gleaming information from Rife Yahoo forums.