NAS devices are the all-in-one kitchen appliance, the jack of all trades of the home network. They can do one thing, they can do many things, and often you don't even need all of the features. While it's great to own a £350 top-of-the-line model, it doesn't mean it's the best solution to your needs. For a lot less money you can buy a versatile NAS that stores files, manages your back-ups and lets you share data over your own network and the internet.
A 2-bay NAS is an excellent option if all of your data fits on a single disk. Since you can buy 4 TB hard drives, that is enough storage for a typical consumer. If you expect your storage needs to grow in the foreseeable future, it's worth investing in a NAS with room for more hard disks. We tested a total of 15 different NAS devices for this round-up, ranging in price from £65 to £350 / €100 to €450.
The most affordable models usually only offer the basic features. As long as you don't need extremely extensive downloading options (more than bittorrent) and are fine with basic internet access via apps and web access, these are good options. The more high-end NAS devices primarily offer faster performance which you'll notice when you put a heavy load on them, and often (but not always) they have more comprehensive features.