I've had mine for 3 weeks now and my old Windows Phone is becoming a distant memory. One thing I like is the Google app that sends you notifications about things you're interested in. I surfed over to the Texas Rangers scores a couple times, and now it sends me Rangers updates when they're playing. It remembers where I parked my car even thought I didn't ask it to. It sends all kinds of tidbits like that, but intelligently, so the clutter is at a minimum. And if you've seen everything you want, you can clear all the notifications with one touch. Very nice.
The Smartlock is pretty groovy too.