Yeah, trouble-free.
I had one of those Octopus watches that looks like a Rolex. If you've seen one you'll see how prolific they are. I had it linked to my credit card and that was ultimate convenience - never actually needing to carry a wallet, but literally having your credit card strapped to your arm (and telling you the time!). In fact, if you ever needed to make an underwater purchase, it was water resistant up to 50m!
Sadly though, the watch itself was not so sturdy. I accidentally dropped it and some of the markings inside the case came loose and interfered with the movement of the hands.
I sent it in, they de-activated it, sent me back the watch broken watch and the cash value that was still on it. The MTR agent said "No more octopus function, only watch function". I looked at the broken, dead watch and thought - yeah, only in Hong Kong.