I have had multiple Android Wear watches including most recently trying the LG watch sport. Android Wear has come a long way and the rotating crown on the LG watch sport is a nice touch. The biggest complaint I have about Android wear is the lack of improvements on the underlying chipset and the fact that that causes battery life to be so poor. I just moved to the Gear S3 Frontier and the battery life is far superior. As others have noted the app ecosystem is not as robust - but I think I can make do with that. The other big issue is the loss of Google Assistant which really has come a long way. S Voice is nowhere near there yet. I still have not been able to get S Voice to work to text or call a specific contact.
I'm using a non Samsung phone and the one thing I seem to lose with that is the ability to view an entire conversation within a text message. I can see the last message and reply to it without issue, but if I want to refer to previous messages in the thread I have to go to the phone.
I have multiple email accounts across two different email apps and all works well there. I like the look of Google Fit and the data it gives me and I found an app that takes the s-fit data and sends it to Google fit so no loss there.
Hope this helps, feel free to ask any specific questions.