The My Cloud EX2 is the latest in WD's My Cloud series of NAS servers and share the same feature set as the original My Cloud and the My Cloud EX4. But it does at least one big thing of its own: In my testing, the new server registered the by far the best performance among the three. On top of that, you can replace/install the internal hard drives very easily.

The My Cloud EX2 continues the friendly pricing set by the previous two coming with the suggested retail price of just $570 for 8TB (or $470 and $370 for 6TB and 4TB, respectively). You can also get it for just $200 with no hard drive included.

In all, with the combination of performance, ease-of-use, affordability and features, the WD My Cloud EX2 fits perfectly in a small home or an office with around five users. For more options of excellent network storage devices, check out this list.

The WD My Cloud EX2 comes with two USB 3.0 ports on the back to host more storage via external hard drives. Dong Ngo/CNET

Design: Dual-bay with tool-less serviceability
Taking the shape of a thick book in stand up position, the My Cloud EX2 shares the same design and physical shape of WD's My Book Studio desktop external hard drive. It has top-facing drive bays that you can access by pressing on the front part of its top and then replace or install internal drives in less than a minute. The server works with all standard 3.5-inch internal hard drives from any vendors. WD says it will honor the three-year warranty even when you use non-WD hard drives.

On the front, the server comes with a few small LED lights that show the status of the power and two internal drives. On the back the server comes with a Gigabit network port and two USB 3.0 ports. The network port is to connect the server to a home network, and the USB ports are to host external hard drives to be either the backup destination of the server or to expand the server's storage space. In my trial, these ports have enough juice to power bus-powered portable drives, such as the WD My Passport.

If you get an EX2 already populated with hard drives, they will be two WD Red drives set up in RAID 1. This is because for a dual-bay server, RAID 1 is the only option that offers data redundancy -- meaning your data remains intact in the event one of the internal drives fails -- and therefore is recommended for the EX2. That said, for now, the top protected capacity of the EX2 is 4TB. You can use the server in RAID 0 to get the maximum 8TB of storage space but this is not recommend due to the high-risk of data loss. (Read more about RAID here.)

While 4TB is a huge amount, it can fill up pretty fast with multiple users. That said, the EX2 is ideal for a household with five users or fewer, even though the server supports up to 10 concurrent users.

The NAS server is shipped with WD Red hard drives but you can also use hard drives from other vendors with it. Dong Ngo/CNET

Plug and play setup, helpful software
Similar to the case of the original My Cloud or the EX4, the My Cloud EX2 is very easy to setup. In fact these servers are so similar that this part of the review is almost the same as found in the two previous reviews.

As soon as the server is plugged in, without needing to do anything else, you can start using it as a backup destination and shared storage space. By default, the server comes with three public share folders called Public, SmartWare, and Time Machine Backup. As the names suggest, the Public folder is for storing public data, and the other two are for backups of Windows and Mac machines, respectively.

From a Windows computer, you can immediately browse for these share folders, using Windows Explorer, and copy data (such as digital content) over. Macs will immediately see the My Cloud as an available destination for Time Machine backup and the My Cloud EX2 will also appear on Finder. All DLNA-enabled network media player devices, such as the WD TV, will also immediately find the content stored on the server for streaming purposes.

That said, if you use the My Cloud EX2 with a group of computers with no need for data privacy among themselves, there's really nothing to setting up the My Cloud, other than plugging it in.

If you want to do more, however, there are a few extra steps. First from a connected computer, just go to wd.com/setup/mycloudex2. Here you can download the WD Setup software (which is about 65MB and takes a few minutes to download on a residential broadband connection). The Setup software will install shortcuts to the server's share folders (so you don't have look for them), to server's Web interface Dashboard, and install WD My Cloud application, which offers another way to browse the content of the server on a computer.

The next part is using the WD My Cloud mobile apps (available for iOS and Android). This is also very easy. From within the same home network, via Wi-Fi, download the app on your mobile device from the Google Play or App Store. Now when you run the app, it will immediately connect to the My Cloud EX2 and create a trust relationship. After this first step, now even when you're out and about, connecting to a different Wi-Fi network or using a cellular connection, the mobile app on your device will maintain access to the My Cloud EX2 server via the Internet. In other words, there's no extra setup or log-in needed to make the app work with the server remotely. Now if you want to add a remote device, such as one belonging to a friend who lives in a different city or country, to the server, you can create an access code and sent it to that device using e-mail. More on this below.

Other than than the WD My Cloud application and the mobile app, the EX2 also comes with a few other applications for computers. These are helpful software for both Macs and PCs, with the exception of the WD SmartWare backup program, which is only available for Windows since Macs already have built-in Time Machine backup. You don't need to install any of these programs for the server to work, however.

The EX2 shares the same Web interface as others in the My Cloud series, which is very organized and self-explanatory. Dong Ngo/CNET

Well-organized Web interface, with built-in app store

To make changes to the settings of the server, including turning its features on and off, adding more users, restricting access, and so on, you will need to use the server's Web interface. To get there, point a connected computer to the server's IP address or click on the Dashboard icon created by the WD Setup software.