My $0.02 on this... I have learned over the years to avoid rapidly A-B'ing my headphones - especially going between Grado and Sennheiser, which have very different sound signatures. When I do this, I tend to not like the new one (i.e. the one I haven't been listening to as much). YMMV, but my brain/ears need time to re-acclimate to the the phones and only then am *I* able to appreciate the subtlety of that headphone's unique sound characteristics. Try just listening to the 325s for an extended period, with high quality source material that you know well and love, and see if you still have the same feeling about your Grados when you are done.