I have a Pebble Smartwatch and it definitely does not have 5-7 days of battery life. More like 1.5 days (2 if your lucky). Also, I do think the fact that Android wear makes so much functionality so easily accessible is a huge deal for smartwatches. You just say "Ok Google". The whole point of a smartwatch is to seamlessly integrate technology in your life. That means our interactions on them need to be quick. You can't get that if you have to poke around the Pebble watch UI for 15 seconds before getting to your app and THEN sending out the text, or checking your calendar etc.
Unlike the sibling posts, I have automatic backlight turned off and it regularly lasts a minimum of 5 days. On the fifth or sixth night, I charge it over night and I'm back at it.
With respect to "OK Google," more often than not, I find myself in places where talking to my watch would strike me as obnoxious: the office, outdoors, the subway, an elevator. Sure it's quick, but again, a button press or two strikes me as being more effective in those situations. I really would only think of using voice commands in my own home, or in the car. I guess it's all a matter of personal preference... I know exactly how the UI of the Pebble app works, and exactly what it's going to do in a certain amount of time when I press a particular button, which feels pretty seamless to me.
Lest I only say good things about Pebble, I have to mention that in a little over a year of ownership I'm on my 4th one: 3 RMAs due to persistent screen defects. This 4th one should be sent back, too, but I've yet to get around to the RMA process again. Two of the RMAs were within 1 year of purchase, and one was beyond, so my credit goes to their customer service.
You must be doing some very intensive things with your Pebble. I have the automatic backlight turned on (turn on when I shake it), and mine regularly lasts 3-5 days, even when I go running regularly, which happens to trip the automatic backlight for most of the run.
I also use it to track yards I go swimming, Runkeeper for tracking my runs, and miscellaneous things like the music app and the Swarm app.
I definitely get many days out of my Pebble (I don't bring the charger on weekend trips, etc).
I completely agree though that the Pebble is best as read-only and notify device. Interacting with it, even to change apps, is a chore. But I don't really see the point of putting a lot of interaction on a watch when, at some point, it's easier to just pull out my phone.
I have Misfit installed on my Pebble which monitors my every step during day + sleeping cycles during night, so basically using accelerometer 24/7 and I'm getting around 3-4 days of battery with that usage.
Also I'm getting notifications every few minutes (email, facebook, skype) + vibration is on.
