I travelled through 9 countries, with only the first and last using the Euro. And I had no problems and very little fees with the NAB Traveller Card- worked in every ATM, you don’t get any ATM fees unless the ATM itself charges one (which, unlike Australia, they don’t- not even in Russia!) and I think it’s 4% currency conversion from your default currency to the foreign one (I kept all my money in AUD until I reached the last country, which saved converting it to Euro and then in to another currency, which involved 2 conversion fees), which isn’t really that much. I was withdrawing when I got to each country and running the money out so that I wasn’t carrying it in to the next country. It was WAY cheaper and easier than having to find a currency conversion place as soon as you got to the next city! I would take out the maximum that the ATM would allow and paying for everything in cash.
If you do end up with excess of a certain currency, make sure you change it in the next country, the further away you get the less likely they are to exchange it, even in an exchange place or bank- as I learnt leaving Latvia with Lat’s remaining and trying to exchange them in Germany!
The NAB travel card is the best one IMO- before I went I did my own comparision between the ANZ, NAB and Commonwealth, as well as Cash Passport and the AMEX one and the NAB one came out the best.