The reason that you've been advised to take euro traveller's cheques is that you (theoretically) pay all the charges before you travel. You should (once again, in theory) be able to get your euros without additional charge but this might well depend upon where you change them. For example, a bank which only opens inconvenient hours and always has lengthy queues might well give you 'face value'. An independent bureau de change, which opens until late at night and offers quick service, might charge a fee.
The cheapest way to obtain euros is almost always by using a debit card at an ATM. The exchange rate is usually close to the 'commercial rate' (rather than the normal, poorer, 'tourist rate') and the charges are generally quite reasonable or even free. How do you get your money without paying charges for cash withdrawals? Dead easy. Instead of heading to a bureau de change to get your traveller's cheques, take your holiday money into any Nationwide branch and open a FlexAccount. Then withdraw your funds, as you need them (with no charges and with a good exchange rate) at any overseas ATM.
Chris