December 2019: The DS218+ is the best home NAS for most people. It's fast & it offers powerful hardware for the price, includes AES-NI hardware encryption acceleration for added security, has upgradable RAM (i added 8Gb more) , and comes with software that’s easy to use.
In addition to speed, the DiskStation 218+ offers a variety of backup and syncing options, plus it has mobile apps for media streaming, file management, and more. It also supports a wide range of third-party apps, such as Plex, BitTorrent Sync, and GitLab. You can use the DS218+ as a home backup device, a media streamer, a mail server, a website-hosting device, a BitTorrent box, or a video surveillance recorder, nearly anything you can do with a Linux computer, while consuming about as much electricity as a couple of LED bulbs.
I'm primarily using this to backup the surveillance videos from my Xiaomi (mi) Security cameras which works seamlessly.
Overall, the DS218+ is an excellent NAS. Its compact body can store two full-size mechanical hard drives; plus, it has a software solution that comes with a beautiful & friendly UI and features that compliment both beginner and advanced users.
For the NAS device’s build quality, it is extremely solid and i really liked that this included a 92mm fan on its rear to keep its internals cool and within its thermal limitations.
If you’re looking for a NAS device, i highly recommend Synology’s DS218+. You won’t go wrong with this choice and it has sufficient power that will last you the next few years.
Note: i can recommend you to buy an 8Gb ram stick for super cheap at åliExpréss (Zifie Ram 8G 1866mhz DDR3L) which will boost the performance to an appreciable margin.
September 2020 update: This NAS has been a stellar backup device for my phone, home PCs, Mi camera storage.
I removed the CCTV camera system & replaced everytime with 16 IP cameras ( TP-Link TAPO C100, C200 & C310) and using with Synology surveillance station software. Its about ₹32,000 extra purchase for 16 IP cameras license for the NAS and was worth it. Synology is so much light years better than the Chinese made surveillance systems available in india.
Overall performance was very good. Recieving firmware updates very frequently.