Amazon shipped me the drives that I needed for my QNAP reviews today so I went ahead and set up he QNAP TS-459 Pro+ tonight. Read on for details!
Here is how QNAP describes the TS-459 Pro+:
Modern business faces the challenge of dramatic growth of digital data, including documents, emails, applications, and so on. To deploy the IT environment with a reliable, affordable and expandable storage center to securely store, share, and back up the digital assets has become an important task for the server managers of the SMB and entry-level enterprise nowadays.
TS-459 Pro+ houses up to four 3.5-inch or 2.5-inch SATA hard disk drives, incorporates Intel® Atom™ 1.8GHz dual core processor and 1GB memory, and is capable of delivering ultra high performance, reliability, and lower power consumption during intensive data transfers. The NAS is an efficient and powerful business storage center with advanced iSCSI services, cross-platform data sharing, and all-in-one server applications. With VMware® Ready™ and Citrix® Ready™ certification, and proven compatibility with Microsoft Hyper-V environment, the NAS is an ideal shared storage solution in the virtualized and clustered environment.
This is a very nice unit and QNAP was good enough to send me one to play with. Installation was pretty easy. First, take out the drive caddies and use the screws provided to mount the drives to the caddies. Then, install the caddies in the chasis, lock them down, connect the unit to your network and power supply, and power it on.
This unit can configure the RAID on the front panel LCD without a PC or Mac, but I opted to install it the old-fashioned way: by using a disc. QNAP provides an installation disc, so I inserted that into my desktop connected to the network, navigated to the Autorun directory and clicked on the Autorun application. The application started the install process.
Choose Install QNAP Finder and select language.
Once installation completes, start QNAP Finder. Once it finds your unit, choose Yes to configure.
Setup website launches. Click Next.

There is Twonky Media Server in the list of processes. Is it preinstalled on the box?
Yes. You can turn it on or off as a toggle selection during installation.