I'm a new owner of a 325e and unfortunately I do not have another Grado to compare it to. Out of the box they sound very nice and I'm sure they will get even better in time.
The only other headphones I have are the Sennheiser HD 280 and an old Sony V6. I did previously use the Eytmotic ER6 with my last player through a portable amp and found the sound signature similar from what I remember which I liked.
In the past (ten years ago) I was turned off by Grado because of some of the negative reviews and at the time what I thought were overzealous fan boy apologists. I thought it was a gamble this time around but now that I have taken a chance based on what most people describe the sound as being, I cant believe that this is the sound I have been looking for my whole life. My only regret is not trying these out sooner. I can see why some may have a love or hate relationship with the Grado brand as these are so far removed then most headphones that I have auditioned that seem to offer something for everyone but are still lacking. I think a case can be made that not all headphones are for everyone and if it sounds good to you that's all that matters.