They will send you one that has been reboxed, but have told me for my 2 replacements(and another crack now on this one) that they are new devices, just may have had damaged boxes/open boxes. Comes with all the normal accessories, plus you keep your charger, so you will get an extra.
I did the advanced replacement, and will again when I feel like calling for my current cracks. You give a credit card, they put a $200 hold on it, send you a 360 (2nd day), then you mail yours back, hold comes off credit card. Pretty easy. I have had no problems. I initially had to send some pics, but they didn't ask for any for the other ones.
It's honestly sad that I will be getting a third replacement. They even sent me the metal band for my current one. It made it 2 months. It's even quite loose on my arm, so not like I put stress on the back.