An update on Gear S battery life.
I got up at 7am this morning, so it was unplugged for 7 hours.
Much, much better today. 4% loss.
So, Gear S can be left overnight if you clear recent apps. I don't know if this is a Tizen limitation.
My quick overview of the Gear S:
1. Looks big at first but it's comfortable on the wrist and doesn't look dorky. The white one would look nice on ladies. I know coz I was speaking to a Samsung rep during the event on Wednesday and she was wearing a white one.
2. Fantastic screen. To be able to squeeze 480x360 on this screen is amazing considering that almost all other screens at this size only offer 240x360. I do read other electronic parts forums so I do know that small screens up to 3.5" tend to be at this lower resolution.
In perspective, my Nokia N82 from 2008 had a 2.4" screen with only 240x320 IINM. And I was still able to watch 2 movies on a 16hr flight and use it as a GPS.
3. Pedometer and other health functions will be useful for some. The pedometer seems to be on all the time.
4. Notifications are managed on the paired phone. Currently I'm pairing it with my Note3 and it is working fine. I just started to use my Note4 today.

You can have vibrate function for notifications and it is quite handy.
5. Phone function: I haven't put in a SIM card yet, but it can make calls using the paired phone. You can dial a number or pick up/reject call on the Gear itself. Speaker is crap though, very tinny. Well you can't expect good sound from such a small device.
6. Battery life seems to indicate you should be able to last a whole day if you use it mostly as a watch, with some calling and notifications. Remember to clear Recent Apps though.
7. Here maps-this looks like something that will be really cool but I haven't fully tested it out yet. Will update more later.
8. Back to battery. ..I beleive it will not last more than 3 hours if you used it as a GPS, and the sad thing is you can't wear it when it is clipped to the charging dock. Upside is that it charges from 30% to 100% in under 2hours.
I'll update once I start using it as a phone.
battery life seems to be a main concern although with Tizen it is supposedly built from scratch