This was my experience. On the day preorders were available I noticed on apple.com that availability for my device (Verizon 6s+ space grey 128GB) was quite limited. The store in Atlantic City had them. Actually after I reserved mine they did not show availability for another so I must have snagged the last one!
The requirements are on the website. State issued ID (DL), passport, etc. And a major credit card. They will do a credit check and it will show a hard pull on your credit just as if you were buying a car, applying for a credit card, etc. So do be prepared for that. I did hear stories that early arrivers were getting declined despite having excellent (FICO 750+) scores. This turned out to be an issue with the bank not having enough resources to process all these applications at once and was fixed later. (I did not have any issues at 12:30PM) but I feel sorry for those that got turned away. My backup plan (since I drove nearly 200 miles!) was to either buy at full price with a CC OR use Edge since I have eligible lines. But the Apple Upgrade program works better for me since I prefer to get a new phone every year and not worry about paying off devices and selling them on Swappa, etc.
In any case I DID have to provide them with my Verizon passcode and four last of my SSN. The credit check requires full SSN obviously. And there's a lot of clicking "I agree" buttons on their little portable point of sale terminals too. The whole process takes maybe five minutes. It was in and out for me because I walked out with a sealed phone. The number I used was on my Note 5 that I had with me and I noticed when I left the store it had an activation message on it meaning its SIM was no longer active. One thing I did notice when I finally did open the box (back in my car at the Caesar's garage) is when I turned on the phone I got the dreaded invalid sim card on the device! I thought Nooooo! I did not want to go back to the Apple store (although the line was ridiculously short for opening day!). I had my 5S with me which is on ATT so I popped its sim in and it worked. Had connectivity immediately, activated and entered itunes info and was good to go. I switched back the original SIM card the phone came with and it came up immediately with VZW, full LTE, etc. Weird, have no idea what was going on.
My CC also showed a hold for $120 and change. It went away after a day. Then another hold which became a charge showed up a few days later. This is the first monthly installment plus the sales tax. The sales tax at Atlantic City is 7% where back home it's 6%. So in theory this cost me 1% more plus me driving with tolls, etc. A trip to the boardwalk and taking the day off is worth it! Plus I have a desired phone on release day! Supply on these is tight!
So unlike carrier financing plans where they make you pay sales tax up front, this one requires no cash payment or credit card payment up front. The original hold I suppose it just to make sure your card is good. It's an unsecured loan, the phone is unlocked and I'm pretty sure (unlike carrier EIPs) if defaulted on the IMEI isn't blacklisted, etc. The balance would just go to collections like any other unpaid debt. I do like how they deduct it from the card automatically so I get some points on it. I'm just glad it isn't like the old days of buying a car where you would be sent a payment book and have to write a check every month! LOL
So after having this phone over the weekend and my wife was playing with it (she had a 6+ and switched to a 6), she decided she wanted to go the same route I did but get the rose gold instead. I hit istocknow.com/live and was watching it like a hawk. Score on Monday (28th), Apple store at Tyson's Corner, VA. Much closer drive. I did the reservation and noticed that you can only reserve it that day! I picked a late time (8:30-9:00) and we headed out after dinner. Got there a few min early and there was a pretty good line, perhaps 40 people. Checked in with a reservation, walked out with the phone in about 10 min. Tax was a bit cheaper than NJ, everything else the same.
Interestingly enough hers worked right out of the box, no sim swapping needed. In minutes were were up online and driving home with Monday Night Football playing courtesy of Verizon NFL pass. I wish that did not count against our monthly data caps but that's another topic altogether!
Now, next year when iphone 7 preorders open I guess we'll do the same with reserving and bring our phones in to the store. From what I'm told they will check your device, make sure no personal info is on it, shows normal wear and tear (cracks, dents, etc. may require an AppleCare incident to resolve) and they trade it in, pay off the installment loan and a new one is opened to start the process all over again. Since I haven't experienced this first hand and don't have a time machine to try it now, it may be different but it's probably a safe bet that's how it will go down.
I can't imagine them scrapping it altogether but you never know.
And it looks like the carriers are starting to respond to this program now. As if they had a choice. I'm surprised that VZW has actually responded to this before ATT! Of course VZW's Edge isn't as attractive to early out people as it used to be as buyouts require the full balance. ATT would let you pay off less and give them the device back for an upgrade. Still not as attractive as Apple Upgrade Program. Two years of Applecare is cheaper than most carrier insurance programs. Verizon's $11/mo. plan covers lost/stolen devices as well. It's really whatever works for you. I've never bought it in the past. But after spending $329 plus tax to get a 6+ replaced that was filled with oil, I think having AC+ makes sense!
Now when upgrading every year you are in fact losing half the AC+ that was bought. Or do they apply that to the new device you're upgrading to (if no claims are made?). These are questions I don't have answers to. But TBH, I really don't care, it's "the cost of doing business" as they say and a plan that lets me have a new phone every year, on release day, without camping out and other nonsense, works for me. I just have that payment of ~ $45/month for the convenience.