I've found the information you provide on your site and on videos posted on Youtube very helpful. Thanks for your work. I'm new to music streaming. I have a SONOS PORT device that I'm using to stream from Spotify. Next step is to rip the ample (600-700) family CD collection and move the data to a NAS for streaming purposes. Based on the information I've seen you present and what I've seen on the Synology site, I've been focusing on the Synology DS220+. 3.5 years ago in a video you posted on the subject of choosing a NAS for purposes of streaming with SONOS devices, you suggested the DS216+ as a viable option. In the intervening years, is there any new information to indicate that the DS220+ isn't a reasonably equivalent choice? Is there something else you might suggest I consider? I also plan to use this device for basic backup of family computers (including a fair number of photos that I'd like to organize), of which there are four. Besides the additional capacity, does the DS720+ give me anything, feature-wise that might be useful enough for me to consider? I reside in the U.S. Thanks in advance.
Yes, DS216+ is an old model that has been now replaced with DS220+. You can easily link it with your SONOS speaker and store all your music on this redundant storage device. Synology also comes with free mobile apps allowing you to back up your pictures and videos and also replace your Dropbox with something better.
DS720+ is a model with twice the performance and the option to add an expansion box if you needed more storage space later. If you are not planning to use multi-user video transcoding, virtual machines, or web server then DS220+ will be a good enough solution.