Love at first wear!
From the unboxing to the first time I put it on my wrist, I have been incredibly pleased with my new Apple Watch Sport (38mm Space Gray with Black Sport Band). I have smaller wrists (160mm) and have worn a Rolex Air King for the last 15 years, so Apple immediately impressed me with a "real watch." It is obvious the team behind Watch really do love watches.
Size-wise, the 38mm Sport is the same thickness as my Rolex, and the overall proportions are similar. It looks just right on my wrist, and the satin gray with black combination works well with my dark hair and complexion. Indeed, the black background screen seems to pop just that much more with the dark case and black strap. Most importantly, the Apple Watch is incredibly comfortable. I don't even feel it.
I'm really amazed with the screen quality and legibility. Every time I glance at it, I'm just impressed with the clarity, colors, and definition.
My previous smart watch was a Moto 360 Android Wear. It was impressive for that edge-to-edge round screen (despite the flat tire at the bottom). Apple Watch, however, blows it away in style, compactness, comfort, clarity, and most importantly, function. Aside from the imperfectly round screen for analog watch faces, the only thing the Moto 360 has on the Apple Watch is the clever dock for your nightstand that turns the watch into a bedside clock. I look forward to Apple or a third party doing something similar.
Already, the Apple Watch counted my walking distance correctly, and it measures my heart rate reliably and accurately, vs. the Moto 360 which more often than not pops up a message "Couldn't read heart rate. Try again." The Moto 360, even when carrying its companion Android phone with me, consistently short-changed walking and running distances by 25-30%. There was no option to set my stride length, even manually.
I could go on, but those are my day-one impressions given my background in many kinds of watches, whether mechanical, digital, calculator, databank, PDA, smart, etc. Really, really, great.