Have you looked into the Argon T60RPs? They are partially vented but lead times are insane as they are modded. Z review and DMS sing it's praises for a budget headphone (<$400).
Before placing an order I plan on trying out a regular T60RP to check if pressure is an issue.
I'd definitely be interested to hear how the Neumann NDH20 do, please reply hear once you audition them. That NAD Viso HP50 is interesting as well, only $200 right now, why not those for work?
I'm also on the same quest for a good high end closed back headphones to take to work so please keep me posted with your progress! The closed back options are even fewer due to this pressure issue.
I should state my signature preferences as background to any of my opinions - I like relaxed, neutral to warm sound signatures, with good sub-bass extension and tamed highs - as I'm very sensitive to overly bright/sibilant headphones (looking at you BeyerDynamic and Grado). Some of my favourite headphones include the Audeze LCD-2+, Sennheiser HD600/650/6XX, the Focal Elears, STAX L-series and the Hifiman HE1000.
I haven't heard the T60RP Argons - but I have had heard the T60RP standard version, which sounds great. I slightly preferred the sound of the Fostex TH610 - however both Fostex headphones aren't true closed backs, they're semi-closed (which could certainly release the pressure built up in the cups and rememdy our issue) but that means it also leaks sound, which makes them unviable in a quiet office. If not for that one flaw, I would have locked in the TH610.
Yesterday, I was able to test out the Neumann NDH20, the BeyerDynamic DT1770 Pro, the Austrian Audio HiX55 and the AKG K361 and K371 .
Neumann NDH20
Great build quality, average comfort, excellent isolation, entirely too dark, verging on muddy. Surprised at people describing them as neutral and detailed.
BeyerDynamic DT1770 Pro
Surprisingly pleased with these, not nearly as harsh in the treble as other Beyers I've tried, excellent build quality and comfort - but can still get a bit hot in the treble and the mids are VERY in your face. Very curious as to how the Drop version compares as they seem to have specifically addressed these issues, however hestitant to buy without auditioning.
Austrian Audio HiX55
Really enjoyed everything about these, from the build, to the comfort, the isolation, to almost all of the sound signature - except for the highs, probably the hottest in the highs of all the headphones I auditioned on the day. I know ASR is very big on EQing - but its not a route I want to pursue with my headphones at this stage.
AKG K361 and K371
This continues a phenomenon that I've seen in the closed-back headphone space, where budget tier headphones provide a more enjoyable experience than their higher end counterparts. These provided excellent comfort and isolation, rich but non fatiguing sound signature, close to neutral but leaning warm - with a few forgivable hot spots in the treble. The K361 actually sounds a bit better than the K371, however the latter is built much better. That said, they just don't bring the detail retrieval or the refinement of the more expensive closed backs. Hopefully AKG build on what they have here.
My current closed back - NAD Viso HP50
A great deal at current prices and fits my aforementioned sound signature preference quite well - but it tames down the highs a bit too much, even for my tastes. Isolation is good - but comfort is only average as the earcups are rather shallow and the headband can cause pain after a few hours.
So at least for now, the hunt for a high end closed back continues! Would love to be able to audition the Aeon X Closed for a week to see if it causes the same issue as other planars did - but can't really see an opportunity for doing so. I still think the Aeon RT/X represents tremendous value at its current price - but people should be weary of the effects that planars, especially closed back planars can have on your hearing.