I've been comparing these again to the K702 65th Anniversary Edition for the last few weeks. Still think my Q701 sounds smoother (and better) overall. For the life of me I can't really detect that much more bass on the 65th. The 65th is still a tad fuller sounding, but barely audible to me. The extra bass and slightly fuller sound wasn't worth $73 for the pads.
I think the only reason the Q701 might sound smoother to me is that my ears are further away from the drivers. Some detail does seem easier to hear on the 65th due to your ears being closer to the driver. Imaging also seems a bit better but I think it's due to less treble and more warmth.
I guess for people that listen to more bassy music and mostly male vocals, the 65th is a good option. Asian pop (especially the kind with female vocals) sounds best to my ears on the Q701. Female vocals sound more distant on the 65th unless it's a song where there is harsh vocals in the recording. Lots of Cantopop is like that.
Tonight I listened to 7 straight tracks with both headphones.
I also found out that the 65th sounds like poop when you have the Q701's outer foam installed.
The only way I'd pass a blind A/B test on them is by listening to harsh music on both or songs with male vocals.
To me there is like a 3-5% difference in sound between them. It's a smaller difference IMO than the K702 vs Q701.
I do love the 65th pads on the K400 so it was worth it just for that.
I wish I now had a K601 to try these pads. They make an even larger difference on the K400 than the Q701 though!
Again, all this depends on preferences. Neither is better. You'll either prefer the 65th sound or the stock Q701.