I went with AT&T Premier for the iPhone 4 launch last year and it was horrible. They were impossible to talk to, they shipped 2 weeks late, and they totally screwed up my credit card. I think almost everyone who ordered through Premier had problems.
I don't think it really makes a difference either way.
My brother preordered his iPhone 4 last year from AT&T and I ordered mine from Apple. Both of them showed up on the exact same day at the same time too.
and 1080p not everyone got them a day early from Apple, only a few did. I know I didn't get mine a day early.
apple.com as I can get an extra 1.6% cash-back via bigcrumbs.
(Also if frequent flyer points are your game, apple.com also partners with the big US carriers -- UA, AA, DL, etc.) for extra bonus points if you use your airlines shopping portal.
If every site works the same, is there a difference?
IOW, will the Apple site know I am eligible for an upgrade through Sprint? Or, do I have to order at the Sprint site to get the discount an d renewed contract?
For my 2g, 3gs, and 4, I have always went through either Apple.com or an Apple store. To me, they seem more organized. Probably, there isn't much difference.