Surprisingly, I love my watch and find myself wearing it all day long. This is coming from a person who never liked wearing watches before, perhaps only to accessorize with a suit.
Just the other night I had a long wait for a restaurant, and I set my countdown timer on the watch so i knew when i had to go back to check in. I went to a bar to get a drink with my date, and it was nice not having to take my phone out of my pocket just to check the countdown timer. Even nicer it was in a complication right on the watch face, and all I had to do was turn my wrist (and not have to press any buttons).
When the restaurant texted me, I got a google voice notification on my watch to let me know, and we left the bar and got back to the restaurant just in time.
At dinner, the waiter talked about the watch, and I showed him a few basic features. The table next to us couldn't help but listen and watch along. When we left, I checked the weather complication on my watch face, and gave my date my jacket since it was a little chilly. While you could do it on the phone, it was so much quicker and a more streamlined experience with the watch. Especially when you are on a date or in a rush. You just turn your wrist instead of taking out your phone, unlocking, opening the weather app, etc.
Just an example of one night where the watch has demonstrated utility, on top of its aesthetics, which I have fallen in love with.
Driving with the watch has been a pleasure. Checking last minute messages from my dates telling me they will be late, or they are ready. One thing I hated doing was getting my phone out of my pocket or from the passenger seat, unlocking it, and checking the notification. The watch has been great for in-car use. (yes, it does turn on when turning the steering wheel, but it doesn't bother me).
It's not perfect. Siri needs work. Some button presses are not responsive. And voice commands need to be more robust. But for a first-gen product, it's great. Future generations with real health tracking features like blood-glucose, blood pressure and oxygenation, etc. will be absolutely killer products that almost everyone must have.
At this price point, for the SS at 700+, it is definitely not a must-have. Even at the $400 aluminum price point, it is not a "must" have. But if you have the spare change, it is definitely a fun and fashionable item that will add utility to your smart device experience.