They are made by apple, they do several things well, and they blend in with the apple eco system if you are into that. I have a series 4 and bought one for my parent/parent's spouse and my sibling - the fall detection and the heart rate/ekg was worth it to me for them to have. The series 5 has an always on display which is the new exciting feature. If you don't need fall/heart alerts and you don't mind flicking your wrist up or touching the screen - then get a series 3 - they work well in the eco system and are on sale all over the place over black friday weekend. I have also had good luck buying apple stuff refurbed on apple's own site and off of Swappa.

I got one way back when my person got sick - I have to keep my phone off or on silent when teaching or in court and I had missed a couple of important attempts by her/her md to contact me - so with the watch, it vibrated to let me to check and showed me the text etc so I could ask for a break or step out of class if I needed. The day she died, I had my phone in my office (as I almost always do - there are phones in the classrooms for emergencies) but my watch alerted me that she was trying to get hold of me to tell me of what was happening with her (it was completely unexpected from the discussion with her and md that same morning) and so I cancelled my class right away and went straight to the hospital - if I hadn't had the watch on - I might not have gotten to her in time to talk to her while she could still talk and before they intubated her etc which she did not want.
So I am a huge fan of the apple watch.