It's a lot of information to take in. Certainly shows more than a simple FFT. It's a tool and in the right hands might do some good things. IMHO, the ear is the best audio spectrum analyzer. Not because it's more precise, but because reveals everything that's important to the listening experience. Think about the attack and decay of a power chord thru a good tube amp. What would that look like on this spectrum analyzer?
For a long time, the HiFi audio industry designed, advertised and sold equipment based on THD measurements and completely failed to measure transient response. The result was that tube equipment, which sounds good to the ear, but does not exhibit super low THD under laboratory conditions was considered inferior. Conversely, solid state equipment that boasted 0.01% THD in the lab often sounded lousy when reproducing music with large dynamics. Eventually the engineers caught on and started designing solid state amplifiers that were up to the task of accurately reproducing the sound of percussion instruments.
