I have an iPhone 6 with Verizon but am going to switch to Sprint service. When I went in to the store the salesperson said that I would need a new phone with the Sprint service programmed in. They said that they could switch it and I could use my existing phone but that the service wouldn't be as good and that I would only have about 50% of the service I would have if I bought a leased their phone. Is this true? or are they just trying to get me to sign up for their leasing program.