ASK NC

I'll be using it as a PLEX server and moving away from cloud services like Dropbox, One drive, Google drive. I have both android and apple phones that need backup and I have my main computer that will also need to be backed up.

I'm new to NAS but I have built my own computers in the past.

DS920+ is a multimedia friendly NAS. You can run Plex server and back up your computers and mobile devices.
It also comes with mobile apps for easy file access. Synology Drive is very similar to Dropbox. You will like it.

I hope this helps.