Buy and try THEN comment
I was a cynic but saw the Sony 2 for not much over 100 quid so took a gamble. I'd expected it to be a gimmick but at that price - what the hell. A year later it's my much loved Casio that's gathering dust. You will never understand the convenience unless you try one. From my perspective the discrete vibration and on screen incoming text/email is a deal maker irrespective of the other apps.
Sure some features are gimmicks. I don't need a device to tell me I've walked 20 miles or spent 90 minutes in the gym, I already know, I was there... Anyway recent research reported that fitness trackers REDUCE the amount of exercise people take because they tend to stop exercising when they reach the tracker's target. But just because some apps are gimmicks (to me, others seem very keen on the fitness widgets) that's not grounds for dismissing the whole concept untried.
Battery life: less than 2 days compares poorly with the 5 years of my Casio! But then that applies smart phones too, I used to have a basic Nokia with 2 week battery, now I'm lucky to get much more than a day from Nexus. It's the same trade off: less battery life, more features.
The watch charges overnight on the bedside cabinet - and it's USB, finding USB power outlets is no problem (I've got an alarm clock with 2 USB outlets so that charges phone & watch)
Of course Apple isn't the way to go just get an Android Wear for a third of the price of the cheapest Apple watch.
I suggest smart-watch deniers try Android Wear for a month and come back here with educated responses based on actual personal experience.