Personally I find travellers' cheques are a pain to get changed whereas you should be able to use your debit and credit cards easily in the big cities. Just remember to let you bank or card issuer know your travel plans, as sometimes they will block transactions in unusual locations. I would also take a reasonable amount of cash in case you have any trouble using your card - US dollars are widely accepted in Vietnam, although you will pay slightly more for things than if you use local currency.

Kind regards,

Olly, your editor