I have ridden the 650b and compared to my five I found :
When you first get on feels very much like a normal five.
Climbs better, it is 3lbs lighter then my 2012 model.
Rolling speed is quicker ( slightly)
As with the five, when this go downhill or technical it comes alive.
Loved the 1×11 setup
Hated the avids
Stealth dropper is a nice touch