I have never heard the HE-4 but I can tell you that my 225e is much better than the HE-560 with the heavy distorted guitars.
Define Better :3, though the HE 560 is for all intensive pourposes a "warm" HE 4, so I've heard the newest HE 560s are warmer than the First Batch, which sucks :/
Though, I'm listening to some Metal Now on the HE 4, Oh wait I should mention I have Beyer Pads on my HE 4... which makes it really aggressive hmm I forgot about that, anyways [I should have my HE 4 measured some day] if you would though define better?
I will say refering back to my Old LA D2k which was epic with metal, on the HM801 the D2k had no Edge in the mids [cuz the hm801 is slow and analog] but on a cleaner source the D2K was pretty epic for Metal, so I think if you had a warmer HE 560, it may be why you didn't like it, as the Grados are pretty aggressive
though my biggest issue with the Senn Grado, is sound stage and it's positioning. It really can't keep up to the HE 4 in terms of layering and speed