I honestly can't think of any particular pros or cons of applying now in branch via your prequalified offer vs waiting 1-2 months and applying online. If they want you to have the card, you'll be approved for it either way. IIRC from when this card was new, if you had a recently opened bank account with them you had to apply for the AR in branch so that the branch banker could call in to have your card pushed past the "Existing customer" stage of the process. If you were to wait 1-2 months, it shouldn't matter if you apply online or in branch.