What I think is good about this is that they are thinking of a new paradigm for UI on a wearable. For Android Wear devices it feels like Google just decided that voice was going to take care of UI, and no decisions about physical controls needed to be made. But there are two problems: voice isn't that reliable, and more importantly, there are a lot of situations where you want to use your watch but not talk to it.
However the best thing I find on the pebble is - Battery Life, - Readability in daylight, - Slim and light weight.
Smart Watches are quite nascent tech and if we get to where we get ones that are amalgamation of all these features, I'll be a content man.