I actually bit the bullet and did an edge on the 6s. I currently have a 6 and my contract was going to run out in Feb. I planned on staying no contract until the 7 arrive and buy one at full retail. Basically with the monthly credit with Verizon edge i end up paying $2.08 a month for an iphone 6s and get to trade it in every year. I can't complain too hard...$24.96 a year and I get a new phone.
I came across another part where VZW is touting that if you decide to keep it, you can, you just keep paying the normal monthly installments as usual instead of larger one-time balance payment to pay off the device like it is at the other carriers.