Just changed my reservation at Park Hyatt Vendome to P+C . My exchange rate was just a tiny bit unfavourable vs the central bank rate, due to rounding I expect.
But the rate is now quoted in euro, so I don't have to worry about the front desk cash exchange rate.
AND
The hotel tax (VAT) is included in the rate, not added on to the converted $300. This may only be for hotels that display their rates with taxes/service included (UK, France, Germany, Osaka (but not Tokyo) are some that I have experience with).
The non-added-tax is another big plus ^