This is the impression I get, after using one for about a week. Not only does it seem rather unfinished, it's also quite buggy (some notifications never disappear, the navigation integration is basically unusable, and there was a point where I was getting no notifications and had to clear data for the Google Play Services app to get them back).
However, when it does work, it works brilliantly and I'm kind of lucky that it doesn't look monstrously big on my wrist, so I think I'm going to stick with it for now.