And additionally I don't like taking my phone with me - not because it is big but because after a few miles I can't directly interact with it via the touch screen because my fingers are too sweaty. So they might be on to something if the UX of the device turns out to be nice.
I don't see this replacing my Garmin watch anytime soon.
So you might be able to get pace through audio.
The bad news (for pebble) is that runners have been using wrist mounted gadgets literally for decades (HRM watches go back to the 1980ies), so they are trying to leave the wrist in the single market where wrist-worn computers are actually established.
However, my SO introduced me to the Flipbelt, and that kind of solved all the problems.
Running and sleep tracking were secondary reasons. I'm glad I chose not to buy as I would have remorse with the "new version" of sorts being presented on Kickstarter.