Chip
I also recently returned from Europe, and the chip in the card worked for the Gatwick express train in London and the Barclay's Cycle Hire bike rentals. It was nice having the peace of mind of primary car rental insurance in Romania.
I can also confirm the credit line does not appear on any of my credit reports, which is nice, as we're applying for a loan, and the $5k or so of vacation expenses we put on the card won't show up and potentially interfere with our loan approval.