Not to rain on anyone's parade here -

- but I do feel I have to note that P/L has allowed me to cancel a winning bid in the past, minus their service charge. And Starwood declined to honor the recent 35 pound/night rate at the Lanesborough which appeared on its website - even though Orbitz later agreed to make up any difference in charges which the Lanesborough property insisted on charging customers who booked through Orbitz website (good on them).
So, who knows...