I have had my Huawei Android watch for over a year and now have a new HTC U11. I have worn a watch since I was in grade school so getting used to that part of the watch was super easy. My big concern was daily charging. I only need to charge it every two days and since I have multiple chargers at home and one at work that has not been an issue. Sure, it would be great if it lasted many days or had solar charging but it has not been the hassle I thought it might be.
When I had my Note 4 running Marshmallow the watch always won when it came to bluetooth which was annoying when I got in the car. With the HTC U11 the phone lets the car win when I start it up. That is great as I want to make and receive calls on the hands free BT in my car always. I don't know if this magic is due to the phone or Nougat but I am darn happy it works.
My watch updated to Android Wear 2.0 some time back. I was using Coffee for SMS support but no longer need to use that. Nice to have a keyboard right on the watch for quick replies. I have tested the drawing aspect as well and it works for sending back an emoji. Rest of the notifications work as expected and that is my favorite part of the watch. See the notification quickly and decide how much attention it needs.
Both of my sons have Zen 2 watches and get a lot of use out of them as well. I have found the watch to be a solid purchase and would dearly miss it should it decide to stop working.
Both the watch and phone have been solid in their pairing. I have not rebooted the watch since I got the new phone. I have rebooted the phone once outside of installing updates when it got overheated on a super hot day where I was also getting sick from heat stroke nearing conditions.