SmartWatch 3
I have many users still using SmartWatch 3. It should work well.
The Sony SW3 has a slightly older version on Android Wear (1.5), where the installation still happens automatically.
Update 2019: If you have connectivity issues with the SW3, please see this post: Connection issues for generation 1 watches
SmartWatch 2
On the other hand, the SW2 was created before Google released Android Wear, hence the SW2 runs a proprietary operating system which prevents it to be compatible with standard software 🙁
Note: you can still use the home screen widgets on your phone’s home screen:
Please watch the product video to see how: