Yes. I agree with you straight out of the box is a bit wow.
Bass has tightened up after 15+ hours burning in (rather than being too boomy - it's the right amount for me). Soundstage gradually widening too.
How different would you describe when comparing the Amperior to the HD 25s?
Glad you're enjoying your Amperior, too. :)
To my ears it's better-sounding than my HD 25-1 and a definite level-up in overall quality. I agree that the bass is tighter. And there's more sonic impact from the Amperior, too, which I prefer.
I don't really want to say any more than that for the time being; I'm burning in the Amperior now and will check back with it in a few hours.
Edited by Windsor - 5/18/12 at 4:11pm