so I got those from drop.com during Black Friday week, with all discounts applied and my "drop cashback" it came down to $100. Was really hard to resist, and cashback was expiring.
Microphone is meh - cuts off all lower freqs, voice sounds unnatural.
But the headphones. For music, even without EQ, - really good. For games - not so much. I have to apply EQ and retry.
Mobile usage - great, and even better with any external DAC, I used Apple USB dongle, beats my laptop or tablet built-in audio. Keep in mind though - those r really open headphones, outside sounds r not blocked at all. If ur in a noisy env (work or bus or car) - I suggest getting closed back headphones.
Volume control is really distracting and annoying for me - I wish they dropped it (pun intended). At first I thought PC38x is "insensitive", but turns out volume was on low.
Headband is OK for me, those two cushions on it r not comfortable at all - bad choice of material.
Earpads - installed r bad, get ur ears hot, I immediately replaced them with (included) velour earpads. Much improved comfort.
As for stiffness and adjusting headband clamping force - I guess my head is just the right size for Senns.

Included cables are both with 3.5mm ends. No 6.5mm love.

Had to dig thru my collection of 3.5-to-6.5 adapters.
Seeing that 58x costs about the same but has no mic, and higher impedance 28 vs 150 Ohm (which is not good for mobile) - I vote for PC38X.