The important competitive advantage is unlimited data.Given that the 4s is a world phone it's the same phone as with any carrier.Sprint's plan will make the cost of ownership the lowest in the US.That is a huge competitive advantage and will make a difference in this economy.I predict that the 4s will sell better at Sprint than at AT&T and Verizon.
Sprint is not offering unlimited data with the IPhone plan. I have sprint and am grandfathered into unlimited data, BUT not if I want an iphone.
Sprint plan if not unlimited has to be significantly more generous to show a distinct cost advantage compared to T and VZ.The 4s is not a WiMAX device, that means low eVDO rev. A speed vis a vis HSPA+.But only AT&T offers HSPA+ and most people I've come across are not keen on T.