As mentioned in the other thread, there are better cheaper options out there. As pointed out in the MoneySavingExpert link, the Halifax clarity credit card wins hands down for me. I have been using it since many years now and is perfect. No charges for using abroad, nor any charges for withdrawing cash. Works out at around £1/month in interest per £100 withdrawn. Also spend £300 and you get £5 cashback (which works out roughly 1.6%). The only thing you need to do is call the customer service before you leave and tell them that you are travelling and you will use the card in another country. They will then remove the restriction for that country (to avoid fraudulent use).
better rate for euros on fairfx
Best rate for Polish Zlotys anyway.
Not a particularly good rate for Turkish Lira - the same is available from other online sellers such as Travelex etc.