A subtle point here for me was that I found the vibration of the Pebble v.1 to still be rather loud and to draw the attention of anyone near me to my wrist. It's rarely mentioned, but I think the biggest feature upgrade when I moved on to the Apple Watch was how subtle the "tap" vibration was. It means that I am unfailingly aware of a notification, timer, or alarm firing, and a person I am in conversation with is never aware that it happened. The ability for it to deliver different patterns of taps is also nice, for instance, turn left or turn right are recognizably different tap patterns when using the watch for navigation.