I've used a variety of different body composition monitors. I love graphs, charts, and tables - especially when I am the subject of them - but it's tedious having to enter data into your own spreadsheet. So the way this scale syncs with the Withings smartphone app to automatically generate graphs and tables is very exciting! :)
For me, trying to gain weight but without increasing body fat percentage, a scale like this is a very useful accessory to my training programme.
The heart rate monitor is a nice addition. I thought the temperature and CO2 readings were a bit silly when I looked at the specifications online, but since I've had the scale, I've been interested to look at those measures every day - one of those things you don't realise you want until you have it!