I wanted to purchase some replacement pads for my MDR 7506s because while they are my favorite headphone, I rarely wear them anymore because of how uncomfortable they are. After about 20 minutes my ears get really hot and feel like they are sweating. Not very enjoyable. I wanted to get plush Beyerdynamics replacement pads, but NO ONE had them in stock online. I asked around in these forums and someone suggested I try the Pearstone replacements as they were supposed to be identical. I was hesitant at first because I've never heard of that company, but they had great reviews on Amazon. I got a pair for $25, shipping included. Let me just say that they are amazing.
If you own a pair of V6s/7506s, really do yourself a favor and buy these. The quality seems great so far. The fit doesn't look as seamless as the stock pads, but they stay on perfectly. Install was really quick and painless, about a minute for each pad.
The best part of these is how comfortable they are. It is like you turned a $150 headphone into a $400 headphone. I've worn them for a few hours and hardly realize they are there. No hot ears, no pain, and no problem with my glasses.
In my opinion these pads haven't changed the sound of the MDRs very much, but I actually enjoy wearing these headphones now, which is why I bought them in the first place!