I initially went through Sprint then canceled pre-order since the $150 trade-in credit is not applicable to 2 year contracts, only monthly installments. I cannot switch to monthly installments since I have other lines on existing contracts.It's here. I showed this to the rep and he agreed Sprint also receives $100 gift card. I was unable to upgrade for unrelated reasons, however, so I can't confirm that he would have eventually actually given me the gift card. But he was convinced.
However, I'm doing the $150 *cash* bonus on trading in old smartphone via Sprint directly instead. For some reason they're also taking off $15/month for switching to the installments, so once I trade in the old phone it'll be like they paid me $44 over the next two years to have upgraded.