I think getting a brand new phone for free is an offer that can't be beat. I think more and more companies are starting to do this because they know the value isn't in the sale price of the phone, it's in the price of the two year contract and beyond.
Verizon has the best offer for the new iPhone, if you want to commit to a two-year Verizon plan. That way, it's a great deal, and Verizon has the best coverage. If you want to just buy the phone, I'd say buy it from AT&T. They have the best rate on it if you are just buying it separately.
According to the two carriers agreements, Any phone. Will match competitor’s ads
Up to $300 for a new phone, including iPhone 6 Credit applied to bill (must wait 2 to 3 billing cycles) Part of standard buy back program. Mean while with verizion you seemed to be locked in more with less money here are the facts. Verizon iPhone 4 / 4S / 5 / 5c $199 gift card (same as cost of iPhone 6 w/ 16GB) 2-year contract required Sept. 30.
Verizon has a very good offer for the new iPhone, but it does not have the best offer. Other competitors are offering almost identical deals- trade in your old iPhone for a gift card. They all have comparatively low options for financing a new phone, and free iPhones with certain contracts. Verizon is a great option, but not necessarily the best.