I bought the first iPod Touch. This is quite similar. It COMPLETELY displaced my home computer, being able to use it anywhere anytime for about 90% of anything I wanted the computer for (enough that I suffered thru making the remaining 10% either work by any means necessary or just dropping that action altogether).
Configuration? Tap the new “Watch” app on your iPhone, point camera at Watch face. Done.
Battery life? intense use for several hours, basic watch function for 3 days, recharge with magnetic-attach induction puck. When battery reaches “it’s dead and not coming back”, you’ll have bought a new Watch already.
Don’t want one anyway? nobody is compelling you to.
The little gadgets still can't displace a good ol qwerty keyboard. I am always surprised when someone tries to use a touch pad device to type large documents. It is painful and my wife wasn't too happy when she had to give up her flip out keyboard for a touch screen. Voice recognition helps, screen swiping across the keyboard helps too. But it will never replace a true keyboard.
Certainly you can always attach an external keyboard. But why not just buy a laptop or a desktop (for about the same price). I know, I am a nonconformist for suggesting this. :)
My son is starting College next year and we will be looking at laptops pretty soon. I like the ultra-slim, ultra-lite laptops that Apple has to offer. But I can't justify the price adder because it is Apple. And it isn't just the laptop that is pricy but the software. Very pricy indeed but will we will stop in the Apple store as a comparison.