Current AT&T user here...plan on checking Verizon's reception in my home before officially porting my number, so I just ordered my 5 setup as a new line.
If I turn it on when it arrives and activate it through iTunes and then see that the reception is good here...do I then have to wait a period of time before porting?
Hard to tell. I don't know if you can do it like that, it would be best to contact Verizon to see.