Several things can happen when you try and use a Premium Pounds:

- The don't know what "pounds" are, so they attempt to credit $100. (Ren Pere Marquette)
- They think that all of Europe is now using Euros, so they attempt to credit $120-ish. (Marriott Wardman Park, DC)
- They attempt to process an actual retail currency purchase, so they attempt to credit $160-ish. (Ren Pere Marquette, Take Two)
- They attempt to post the certificate as an adjustment. Read the back - clearly states "credit", not adjustment. (Ren Seattle)
- They get it right the first time, because the front desk agent is trained pull up a forex site and get a fresh market quote, and then apply the credit. (Marriott Royal Palms in Orlando, probably because they get lots of British folks there and are familiar with the certificates.)

I have campaigned successfully - at the front desk, with the manager if needed, to get the first three scenarios resolved.

I mildly argued the adj/credit issue the first time it happened in Seattle, but didn't take it too far: I've gotten to know the front desk pretty well from repeated stays there, and they treat me extremely well other than misprocessing the occasional PP cert. (For those who don't know: an adjustment reduces the points-qualifying revenue whereas a credit does not.)