Guys, I think the only real difference between the 'Travel' card and the 'Debit' card is that the card says 'Credit' instead of 'Debit', and the card is shiny (+1 for that). It actually works as a debit card, as deposits are directly held on your account. Still not the -real- benefits of a creditcard.
Both cards work fine at places where they accept mastercard creditcards (they use the same system), I guess its intended to 'mislead' humans checking whether is a credit or debit card.
I just went to the US for a month and used my Bunq debitcard for all direct payments. Only for deposits at hotels and on rental cars I used a VISA creditcard. Not because I couldn't use my debit card, but because I didn't want them to freeze my money on the account.