On a flight to Scotland (actually 2- one to NY, and one to Shannon) last summer, I found the problems due to stress, anxiety, and lack of mobility during flight.
On the flight back, trying to get to a gate almost a mile's walk
with no moving walkways or escalators working, and the need to
connect very quickly cause the flight from Shannon started 1-1/2 hrs late (only had time for a 1 hr 50 minute layover to connect- only 20 mins with the delay) and no wheelchairs in sight - I was a wreck trying to get thry Kennedy Airport.
I don't think cabin pressure has anything to do with it,
but barometric pressure can affect me.
Its probably a combination of all factors that make flying with PN, problematical.
Depends on urgency and need to get to where you want to go,
to compromise and decide to fly on long flights.
Shorter flights (the connecting one- from D.C to NY)
aren't as much of a problem, it seems.
But the stress factor is always there with controls, immigration, searches, shoes off, bags lost, and on, and on and...........!!