I'd add a point 1a. to your list
Customisable watchface.
My Pebble has a vague time watchface operating almost constantly - If I need to know the precise time I can find it readily enough, but generally all I want to know is that it's 'about quarter to ten', or 'nearly half past three'.
By the looks of it, I'd have to spend £50 more than the original cost of the Pebble to replace it with a device which advertises a shorter battery life, doesn't seem quite as customisable and, by default, contains a whole lot of *crap* I don't actually want.
*crap being heart rate monitoring, breathing guides, cardio-fitness indicators. Fitbit - the detail is in the company name - based around fitness tracking with some 'watchiness' and notifications tacked on. I want it from the other direction, but without the fitness stuff tacked on.