Hi Stedan
Good luck with the use of the card, but would agree with Black Cat - don't put all your eggs in one basket.
It's all very well for these people saying you'll get a fantastic rate, but what use is that if your card gets swallowed up by a rogue machine, you lose it, or an "admin" problem arises. We had a power cut for about 6 hours last week - ATM machines not a lot if use then. The truth is the improved rate is maybe 1 or 2 cents a pound, hardly a fortune. Take it and use it by all means, but take more than 200 euros in cash.
The rate on the street is normally pretty good here, so take a bit of spare Sterling, that way if you don't use it, you'll have no commission to pay changing it back.
Enjoy your holiday.
PS Never keep all your cash / cards in one place. We had a guy leave his wallet behind in our bar last week, and it was crammed with cards, cash etc. Fortunately for him we were honest and he got it back in full, but his holiday was shot if he hadn't been so lucky