My Experience with AP.
You get two copies. However give only one to the Immigration Officer. He will take it and stamp on it ( just like they do on I-94) and give it back to you. Additionally he will also give you an I-94.
Both will be stamped with "Paroled until MM-DD-YYYY POE").
Each AP is valid for 1 time. Also, if you are entering on AP there is a possibility of second interview. This is usual procedure. In addition to meeting the Immigration officer as usual, you will be asked to meet another immigration officer. They may ask you some questions or they may just stamp your AP and I-94 and let you in. So, as a backup, take the previous W2s and recent paystubs.
Hope this helps.