Over the past few months I've been using the pebble, galaxy gear and sony smart watch 2 ( the last two only since Christmas).
I enjoy using tech (and get to use quote a bit through work and mobile initiatives) and use a mixture of android and iOS devices. However, I stopped wearing watches several years ago. In the end I've decided that none of these smart watches give me enough incentive to start wearing a watch. However, if I was to wear one I'd use the pebble, and possibly (with a few enhancements) the sony watch.
I got the pebble watch a few months back through the kickstarter project. On getting it I liked the design and feel of the watch and set about pairing it first to an iPhone 5 (which went very smoothly), then to an htc one (fairly smooth) and to a Samsung s4 (problematic). It worked best with the iPhone ( for example controlling the audio app currently being used and showing relevant info for that app- unlike android which required an audio app to be preselected and then showed information in the watch for that app, even if something else was playing). The battery life and waterproofness were great. If I wore a watch I'd use this one.
Sony smart watch 2
I wasn't expecting a lot but I was pleasantly surprised to have a mini android screen with apps, home key etc. and by and large it worked well (a few navigational inconsistencies). It's light and feels pleasant to wear. However, having to press the on button to use it is a bit fiddle, I'd have preferred an LG style double tap to turn it on. Unfortunately, whilst you can see emails etc, you can't mark them as read which means dealing with them on my phone as well. The mini USB charging cable was good (I've lots of those).
Samsung galaxy gear
This started off well, if feels nice to wear, but went downhill from there. It only pairs with Samsung devices (luckily I'd replaced my corporate s4 with a note 3). It uses a proprietary charger, which given the short battery life compared to the pebble is a nuisance. Functionality felt more limited than the sony smart watch which at least seemed more like a more powerful android device. Hardware on the gear is good- but things like the camera inbuilt onto the watch strap seem a costly feature that personally I wouldn't see myself using. Currently this is languishing In a bag ready to go back. I was hoping for more from Samsung.
It'll be interesting to see if apple can inject some practical appeal into the smart watch concept, or LG who have taken some strides forwards in the innovation stakes (and have the double tap to turn on feature at their fingertips).
For now though I'll stick with phones and tablets. And if those aren't to hand I can always ask someone the time.