Re: Benefits?
I like being able to quickly check my notifications without digging out my phone, and occasionally being able to control my music from my wrist is also useful too. My Pebble gets about 10-14 days on one charge, but I usually charge it once a week.
If that seems useful to you then it's worth it, if not, stick with a normal watch.
That said, a lot of people seem to like the fitness stuff some watches have. Can't see the point myself but fortunately there's a watch out there for everyone, smart or 'dumb'.
It's interesting that price rarely comes up as a factor, because it's hard to say if paying £80 for a Pebble is a good or bad deal. Sure, I could by a cheap Casio for less than a tenner, or I could buy a fancy Breitling for tens of thousands, and yet they both do the same job. I'm not sure where various smart watches fit into that.