Fitting the Ori pads should not be hard but you will either have to buy some velour pads ($10) to get a pair of mounting rings or cut them out of the stock Focus pads ($40 replacement cost).I'm considering these Ori pads not because of sound but for comfort compared to the stock pads. Can you say a few more words about this? Although the he560 is considered over ear, it actually feels more like on-ears to me. Cups are way too small, and they squash my ears/make them sore.
Are they relatively easy to put on? ZMF website says they fit Hifiman headphones.
As for the sonics, my initial impression of these headphones has only deepened. They are better than the 400i but also share the 400i's sibilance problem with pop and rock music. On both headphones, classical music sounds excellent with not a trace of sibilance that I can hear. I wonder if anybody can account for why pop and rock sounds sibilant on the he560 and 400i and why this problem doesn't affect classical music.
You might also want to bend the metal headband so that the ear pads are not smashed together when not being used which is what I think might shorten the life of the Focus pads. I had to bend mine quite a bit since the clamping force was way too high for me and like I noted I don't like having the pads always pressed together.