I'll say it's a matter of taste and how you like your earphones. I tend to listen in a quite room and don't have them turned up a lot and I love the SR325s. I also love the Senn HD600s and 650s and plan to get a pair eventually but that'll also probably push me in to the "have to buy an amp" situation.

I also don't find the SR325s uncomfortable fitwise, I do have a big head so maybe that helps.

Either way I'd suggest trying to find a local dealer that has both and give them a shot. I'd say they're both great but in different ways. The Senns are a more refined product in terms of build, feel and comfort however. You need to take care of the Grados and they'll take care of you, otherwise they don't look like they'll hold up too well.

I disagree however that the 325s are little more than refined 80s. On paper perhaps but that's it.