... would a 2 hours-layover be enough??

One more question: As it is especially titeled as an ARRIVAL service, can I definitivly use that service, say, arriving from Asia in F and continuing within Europe in C?! At LH page it is stated that the day-room is available at presentation of a VALID boarding card. How? When I already HAVE arrived, - and it seems to be an arrival-only service -, I do not have a VALID F-boarding pass anymore, do I?! Maybe only transiting from F to F?