Having just recently bought Pebble 2 SE I have some things to say about the product. Unlike a smartphone Pebble has a benefit of staying always with you, thus it is better than a smartphone for things like habit tracking, habit reversal therapy, time tracking. It reduces friction from having to reach out for your phone because it is always on your wrist and it has this great feature of quick actions. Basically you can assign any or all of its 4 buttons to launch an app or perform an action on long-press. This is invaluable.

Another great feature is smart alarm. It works similarly to Sleep As Android and suchlike but you don't have to sleep with your smartphone on your bed.

Other than that it can do notifications, quick replies, music player remote control, show you two days of calendar appointments, weather, countdown to next Apple announcement and last but not least time and date.

What I'm missing is the ability to create voice notes or having a real smart voice assistant like Google Now. It has its alternatives which are IMHO not near as good. The hardware is not a limiting factor here - it has a microphone.

Always-on screen and at least 5 days of battery life with pretty fast charging are not bad things either.

The actual fitness-tracking thing, the step counter, is not very precise and it is only good to make sure that you get enough movement.

So all in all it is not a fitness tracker. It is more of a lifestyle companion that can help you to keep on schedule, form new habits and make better use of your time. It would be best marketed to GTD/time management crowd than to fitness enthusiast who have much much better fitness tracking devices.