My grandfather had a saying -- a place for everything, and everything in its place. It turns out that I'm not as tidy as he was, and I have a tendency to... misplace things. For me, have been a total game-changer, and I have them attached to my keys, embedded in my bags and luggage, and even have one in my car and e-bike.
The SmartLock is quite big and bulky as travel padlocks go — it weighs about 3.5 ounces — but it combines two functions in one. And that bulkiness gives the padlock a decent level of resistance to physical attack. You're not going to break this with your hands or a small multitool.