My watch came two weeks ago, the day I left for a 2-week vacation. So, I did not get to touch it until I returned last night. Today is my first day. I was already a little familiar, because my daughter has had hers since early May, and my Dad has had his since the day after launch day.
I am liking it so far. I did a couple try-ons at the Apple store, and one of the reasons that I preferred the sport was the weight compared to the SS watch. Still, I am surprised at how light it feels on my wrist after most of a day. I have worn a nice stainless watch nearly every day for the past 20 year. I knew this would be lighter, but it feels weightless compared to my dress watch.
I agree that a lot of the apps and glances are slow. Also, the raise to read it is slower than I would like. Since I am used to wearing watch already, I expect instant response. It feels like it takes a couple seconds to pop the display from when my eye is expecting something.
I did my 5 mile daily run with the watch today alongside my Garmin 910XT. It was less than 2% error on the distance, which way exceeded my expectations. (I did have my iPhone with me on the run to calibrate, so that may have helped with the accuracy.) And, it matched the Garmin's average HR exactly. I wish that the workout app had a way to see pace and HR data by mile split. (It may be in there somewhere, but I am still learning.)
I cannot decide which glances I want and in what order. That will probably take a bit of use to decide on.
The App Layout UI on the iPhone is a total pain in the butt. The app shifts stuff too aggressively and can make it difficult to get things where you want them until the second or third try.
I like the watch faces, and especially the extra data fields that I can set up. Like the glances, it will probably take a little use before I settle on a favorite configuration. My biggest disappoint is the Mickey Mouse face. I wanted to use that one, because it is so happy and frivolous. But, it is kind of hard to accurately read the time, so I quit using it after a few hours. It is always there for me, if I want to read the happiest time on earth.
After just one day, it does not seem like a game changer to me, just cool and fun. It is replacing my other watches for everyday wear, so I principally bought it as a watch with some other cool capabilities.