I've had it for a few months on my Nexus 7. In summary its travel and shopping push notifications. I had the usual intense short lived "oh that's really cool" reaction and haven't used it since then and its had no measurable impact on my life. Kinda like my relationship with facebook and linkedin and twitter.
In the eternal wheel of IT, where nothing is ever really invented, merely recycled every couple years, this is the reincarnation of the pointcast internet screensaver app from the mid 90s. Back then the complaint was it was spammy and didn't provide real value, so after a similar intense publicity wave quieted, they dried up and blew away with the wind, until now (literally, "Now", get the pun? Yeah well bad pun; bad puns never really go away just get recycled later...)
Google Reader = News Feed
Google Now = Life Feed