>sing the new headphones will automatically make you pick up on details on songs you have heard many times

Honestly, the Grados and the XS's have the same amount of bass but the XS's bass is higher quality. It sounds tighter and more defined where the boundaries are, compared to the somewhat flabby vagueness of the Grados. Also, A/Bing them, the Gardo's midrange sounds definitely more nasally with respect to vocals.

But here's the weird thing, when I first got the XS. I plugged them into my pc without any amp and on one song I got a brief second of incredible imaging/soundstage where I heard the snare moving away from me every time it was hit.

I thought that was a sure sign of great things to come, but I have yet to hear that effect again. I thought getting a quality Amp would make it possible since I was under driving them. But alas, no dice. Now, the imaging on songs sound like everything is reversed because vocals sound like they're coming from the back of my head and all the instruments are to the 9 and 3 o'clock. I have yet to hear a true Front center channel or a smooth sweep from side to side.