There was a very recent thread on this
I've had my Blackvue (400hd) for about 4 years now , its been trouble free, i remove and format the cards every now and then maybe every 6 months and havent had a card go south on my , its been fit and forget
I have a G1W in my daily as the blackvue or any gps based camera can interfere with DAB radio , it cost me about £45 all in and records almost as well still 1080p but it has a screen and is much larger but i have had a card go on that one and it just stops recording after 5 mins, these cards dont last forever though you should consider changing them every 12 months really
To be honest the thing that really swings it for me is the Blackvue software its really easy to view and save your videos and most of all find the bit you want quickly
Dont know what the 650 is like , havent used one . Personally I dont think a rear facing one is as important.