Not so much a new pair, more of a pair reborn.
One of the pads of my HiFiMan HE400i fell apart a few days ago and the other one followed when I inspected it. I looked at the cheapy (£16) replacement pads but they were all flat, not angled like the originals, so I was going to pull the trigger on a pair of Brainwavz angled pads but before I did I saw the Dekoni Sheepskin pads for the HiFiMan HE series, with the installation ring already fitted. So £55 later, though next day delivery was free, and they were on there way. I got them Saturday morning and after some head scratching, watching a video and then some pushing, prodding and twisting and my HE400i's were better than new.
I put them on, plugged them in and thought - ack, they sound weird. I had the same thought when I first listened to my HD650's, so I knew that brain burn in was a thing. As the minutes went by I just started grinning, I couldn't help it - they sounded insanely good, much better than they did originally. One area where the HE400i always came up short was in the lower bass, it rolled off a bit too soon, well not any more - these things now have a real grunt and slam low down. I was using them with a 6db bass boost using the JRiver parametric equalizer but now I'm running them with no EQ and they sound even better. £55 well spent