You can apply for both cards and use them together for different travel expenses. But if you need to choose one, think of what you are going to use the miles for. The Arrival Plus card comes with fixed-value points which are great to cover some incidental travel expenses like hotel stays, renal cars or cruises. Also, if you need to fly with the airline other than Lufthansa and its partners, the Arrival Plus card will come in handy, because bonus miles can be redeemed with any airline. The Miles & More® Premier World MasterCard® is good for redeeming miles at particular airlines (Lufthansa and its partners), because thus you will use miles at their full potential.