Ended up trying the SR60e at the Schiitr, and it was next to many higher end headphones, including Grados own higher end GS2000 and PS2000 or some variant of those. The SR60e sounded so much better than those two, I couldn't believe it. I don't know what Grado did to the high end models and perhaps the less said the better... but the SR60 is legitimately an awesome sounding headphone for the price.

This is standard in the audio world in genral. This is why the very few wireless headphones that have a true analog input for unpowered playback tend to sound like rubbish. The analog path on those specific headphones don't apply the DSP, and you're getting the raw output of those drivers.

DSP tuning unlocks the potential in many drivers that otherwise are not tuned.