I just got the C Flow a couple days ago, with the perforated headband pad.
I admire the spirit of minimizing the weight as much as possible, but man it is not comfortable for those of us with big heads.
When the perforated pad is pushed against the thin headbands, the 2 ridges in the center act as 2 pressure points that gave me headaches.
My solution was to take out the pad, and cover the rest of the headband with a cover from Amazon.
It's now a lot more comfortable, but the downside is that it's no longer adjustable for anyone else to use.
Hope this helps the next person with this problem.
p.s. There are headband covers with cushions as well, and I imagine they're even more comfortable.
But they add extra height, and would make the cups sit too far up with my head size.
Guess I should count myself lucky that the headband size fits me exactly. Thanks Dan!