Hi Lawrence
I don't think an alternative DEBIT card exists. All the others that you see recommended are CREDIT cards. At least Nationwide has a good exchange rate (as you have said) and I think this largely makes up for the downside of now having fees. Some other cards, especially the pre loaded ones have not so good exchange rates - they have to make their profit somewhere!
So I am sticking with Nationwide, for the present at least, but will try to minimise the fees by drawing larger amounts less frequently, and maximising use of the credit card for payments (NOT DRAWING CASH). There are still no fees on Nationwide's Credit Card, which also has a good exchange rate.