The fast dual-core processor helps keep the DS414j moving data at a decent rate across the Gigabit network interface, and taking backups becomes a lot quicker thanks to the USB 3.0 port at the back.
It's also very quiet in operation, even with two cooling fans. Also, the appliance automatically powers down the drives when not in use and can switch itself off when not needed – overnight, for example (and it turns itself back on again when it is needed once more).
As with all Synology boxes it's the DSM software that really makes the appliance stand out enabling the DS414j to be used both as a NAS box and an iSCSI target for network file servers. More than that it offers more or less everything you can get on a Windows file server but in a much simpler format managed through a browser. It's even got its own apps to do everything from handle email to monitor and manage IP surveillance cameras.
The cumbersome disk-loading mechanism is one of the biggest disappointments on the DS414j along with the lack of support for hot swapping. That said, it's rare for small businesses to need to swap disks in and out that often, and if this is an issue then the big brother DS414 has this capability and a lot more besides, for not a lot more money.
Likewise we were disappointed to find only one USB 3.0 port at the rear of the DS414j, although this will mostly be used to attach an external backup disk so only having one isn't a major issue. The other port can still be used to share a printer at the same time.
The single Gigabit network port is more of an issue. A second wouldn't do much to improve throughput but it would allow for more flexible configuration. For example, it would allow the NAS appliance to be independently connected to two VLANs. If you need this option, the more expensive DS414 has two Gigabit ports.
Quick enough to cope with file sharing as well as hosting email and other applications normally run on a Windows or Linux server, the DS414j ticks most of the boxes for a small business NAS appliance. At 20TB it's also got the necessary capacity and, with four disks, the redundancy to go with it, plus a USB 3.0 port to support fast backups. Synology's DSM is a delight as always but the DS414j is a little on the basic side especially compared to its big brother – the DS414, without the "j" – which is quicker, slicker, and also not that much more expensive.