What uality flac would be best for the y2

just placed an order for the y2, i was gonna start downloading all my music in flacs beforehand, so i was wondering whats the best quality flac i should get for the y2 16bit or 24 bit lossless?.
I have heard that the y2 has a decent output but would the 24 bit provide a batter quality or should i just save sm space and go with 16 bits