The sound is so pleasant and captivating that I have been dispensing with listening to the wired B&W PX-8 and Quad Era—1 through the Audioquest dragon fly cobalt…
Top marks, really!

These headphones have a relatively clean sound with a taut natural bass. I really enjoy their sound signature and prefer this over overblown bass.
They sound great with various music genres and I think they could be equalised to suit anybody's taste.
They represent great value for the sound they produce in today's market.
I buy headphones based on sound quality and only use ANC occasionally. If ANC is more important to you other brands do it slightly better but I think their sound suffers for it.
If I had any negatives it would be that the yokes are not made from aluminium to ensure longevity, after all the batteries can be replaced so I hope the arms last for years. The only other small thing is that they wear quite large on the head other designs are smaller and neater. Not a deal breaker!
Cambridge please tweak the EQ app so that you can overwrite one you created and saved earlier if you tweak something it would be good if it autosaved rather than having to create a new EQ slot.
Otherwise just buy these headphones they are so good and if you still are not sure they currently have a 60 day return.

i use them in my everyday working environment...
why shall all of my colleagues ever be this loud?

ANC works flawlessly to filter out their phonetalks and chit-chat... i'm watching them move their lips like on a tv with the volume turned all the way down and love every bit of that... even the loud colleague who did cut through my previous Sony WH-1000XM 4 ANC brickwall, with my new Melomania P100 now stays put – and ssh.

fit-wise, headband distributes P100 mass nice and easy off my head... which is a tad on the wide side of things, at 62cm / 24in diameter – and the side-force that keeps ear pads snug on my ears is perfectly balanced, neither too strong nor too weak.

battery life is just... whoa, dream-like long: i cover the whole 4-day-in-presence weekly office stint with one single charge, and ANC switched on – can't really ask for more, no way!

the choice of material across all surfaces is spot-on: vegan-leather ear pads don't turn as gleaming-oily as those on the WH-1000XM4 – and i don't have to wipe them all off before putting them back in their case (with the added bonus of fabric-covered headband, too).

i kept my notes on their sonic behaviour as last in my minute – because their so honestly enjoyable, never overwhelming, nor sterile at all, that i'm newly rediscovering the fun with albums off the most extreme ends of sonic latitude: from medieval to metal, electro to classical, folk to chamber (and experimental / nordic jazz in between), you can easily reach out and touch any voice or signal or instrument in the mix, and at any playback level.

Melomania Connect app (i'm from the iOS / macOS hemisphere) does the job nice and easy – feels more solid and quicker than the old Melomania one, and the firmware update works like a charm, blazing fast and perfectly documented.

what's left to say?

that the option of having factory-true replacement ear pads, of the exact quality of those they came with, is a major turning point for me – along with the option to replace their battery when the time will come, will make me even more reluctant to turn to another make in the future.

i can't ask for more, really... you just nailed them – damn right, at first try... bravo, Cambridge Audio, chapeau!

These headphones must be the king of value. This, however, is not to say that buying something 50% to even 90% or even 100% more expensive in some cases will necessarily give you better sound.

Bass is responsive and effortless, absolutely lovely and never overbearing.
Highs are crisp and never disappoint but somewhere in the mid to high-mid range, and only in certain tracks, there seems to be an overexposure.
Low-mids are plenty nice.

About the sound stage, dynamic range, and track separation, they are just enough - this means of course that you can get away with it and have a good listen, but that it also makes you to desire 'just a little more'. For the price all of these important elements are irreproachable ofc. (I've just listened to a €50k Perlisten S7t based setup so I might be a little sensitised to these in particular).

All in all, very happy with the purchase, I wanted an affordable pair with Aptx lossless and these have surpassed my expectations in more than one way which is fantastic.

For the next iteration if you can improve just a little bit the soundstage, dynamism (attack speed etc), and track separation, while working of that (potential) mids overexposure, I would happily purchase for up to £360-£380 (from £500 onwards I'd be expecting magnetic planars).

Nitpicking aside, very happy with what I got :)