I think the 17 is the right size unless you want to wear it loose. I was fitted at the Cartier store and bought a 16. It fit snug. I was a bit concerned because you could feel it at first, but you soon get used to it. The SA at Cartier said it's better to fit snug because it will prevent it from banging around too much and scratching. You do need to be okay with it scratching. I've had it for only a month and have several noticeable scratches, but figure it's unpreventable.
I was just at Cartier in San Francisco this past week picking up my watch that was getting serviced. I inquired about the cost of polishing the Love Bracelet and he said the cost to polish was $110. I was thinking of polishing my white gold watch and it's over 10 years old and he told me the cost for the watch was $165. The guy told me if I want to bring in the bracelet at the same time he would comp the polishing charge on the bracelet. But, I just recently got the bracelet so not sure if I would take advantage of it unless I wait another 10 years. They recommended I only polish every 10 years. Nice cusomer service though. He told me they need to send the watch and bracelet to NYC to polish as they don't have the equipment in SF. Not sure about other locations though. I should have inquired about the steam cleaning.