The major downside to the EARS is the high Q (peaky) response around 4.5kHz. This makes it easier for any compensation to be thrown off if the microphones inside the EARS shift. It should be noted that I have not had any issues related to this. I believe Oratory did an analysis of the EARS which showed it do more than decent job. He actually has a bunch of data from it. I know early on, he wasn't a believer. As a learning tool, very useful. The stuff on accuracy is a fool's errand. I know that different pinna will yield responses that will vary depending upon headphone regardless of compensation. Not every person will have ears and related structures representative of the GRAS.