I've been watching this price for a while, looking to finally upgrade my original Vivofit.
It seems like the best price around by a fair stretch!
DCRainmaker did a hands on with the device here - https://www.dcrainmaker.com/2016/02/garmins-vivoactivehr-vivofit3.html
The main perks for me are the 1 year battery life, it's backlit, and MoveIQ.
Same price at Currys/PC World but Quidco.