I've had the scale for over a year now. It is not only a beautiful device, but I've also found it to be rock solid functionally.
Setup was easy, I've had no hardware problems, and I've gone through I believe one set of batteries in that year.
As far as online/application functionality all I really use is the google health integration. Now that Google is closing that service I'm expecting to see them do MS Health Vault integration instead. The mobile app is fine but I just never use it. The multi user stuff works better than you'd think, too. Strangers stand on it all the time, and my girlfriend uses it as well and it accurately splits our data out every time.
It was my first quantified self purchase and since then I've bought fitbit and a few other things with much more mixed results. I can't recommend the WiThings scale enough.