....your card will be charged forex fee when you travel abroad.
If you pay for a hotel abroad in GBP you may lose anyway since the exchange rate applied will always include a margin for the vendor.
I travel abroad a lot so rather than use forex cash I use a sterling based credit card which offers the Mastercard interbank rate without an additional fee for as many of my purchases as possible.
There is an excellent explanation on how to choose a suitable card on MoneySavingExpert.com
at this page