i always thought laid back/forward is similar to speed of attack, agressiveness and not actual soundstage, depth and perception.
I used to think the HD580 was laid back/veiled but driven by a proper amp its a very balanced and transparent headphone. The grado on the other hand sounds very aggressive, with an attack to each of its note. I dont know how it does that but its definitely there. its almost like the tempo has been turned up a notch.
there's an australian rock band called the superjesus. Though rock, they sound laid back live/on stage and with the sennheisers but some how when paired with the Grado, it pushes the sound to the edge. the signature sound is glorious and fast. the sennheiser vs grado is likened to the solid state vs tube debate.