The PO used to quiet good, only knocking off 2 or 3 cents from the bank rate.
Now it's 6 or 7. Greedy. No commission my ar*e.
After using them for about 15 years I have voted with my wallet and gone eslewhere.
I believe the PO use two different exchange rates, one for over the counter sales and one for online sales, the online rate has been pretty competitive whenever I've checked, and if you order over £500 you get free next day delivery to home or nominated Post Office.
I ordered mine from PO online on 2nd June at 1.1231 €/£, and received it next day - no hassle, well happy
Notice today's online rate has dropped back to 1.0934, so happier still I did it when I did