Can I use this NAS to store my entire Blue Ray collection 1:1, for example, is that possible and if so, how? I would like to be able to store my collections in this way instead of on Blue Rays. Will the quality then remain 1:1?

Different processor, more ports and of course the price ;)

When it comes to hardware transcoding, the DS216play is slightly ahead. It also supports the H.265 (successor to H.264) codec. But that is also the only advantage of the DS216play. Both NAS systems can accommodate 2 hard disks and manage a maximum of 16 TB.

google DS261 play II difference, there are more detailed information ;-)