Slightly off topic:
Given the low number of PE equipped flights/aircraft in the fleet, I think being ticketed in PE gives people a severe disadvantage when it comes to flexibility. For an example: there's barely one flight a day between HKG to LHR and when I attempted to change my flight to a later flight in the evening, even when I said I was willing to downgrade to economy, they told me the system would not allow them to do such a booking. I feel like they should allow PE tickets to be booked as Economy tickets if we need, if they can downgrade for an equipment change without compensation.
I feel like I would be much better served paying for a higher ticket Y class ticket for the flexibility.