As for the more advanced features, such as the UPnP multimedia server can be configured, too, and the unit offers an excellent frontend for each. Also, there's a download manager that can do single files as well as BitTorrent. However, the BitTorrent client can't do encrypted connections, so those of us on Comcast and the like are out of luck.
For some speed testing, I used Cygwin's time and cp to copy a 593,914 kB file from my Windows XP machine to the TS-109, and then back. I did this with all units plugged into a Linksys WRT54GS wireless router/switch. I think most users will use Samba (Windows sharing, for those who have not heard of the name previously), but there's a niche of which I am a member that will prefer NFS, so I did that, too, using my Ubuntu workstation.
I tried FTP, as well, and its speeds were comparable to NFS. However, FTP over SSL was about 1.7 MB/s write, and about 1.0 MB/s read.
I wish I had a smaller gigabit switch to see how these transfer on that. I'd imagine it would be quite high, at least on the Windows XP box, since both it and the TS-109 have SATA 3 Gb/s and gigabit Ethernet. Perhaps I will also look into NFS mounts on Windows...
In further investigation of the TS-109's file transfer capabilities, I also tried SFTP. However, there is no way to enable SFTP. This would be great to have in a future release of the server instead of FTP over SSL. Instead, using my Ubuntu box, I simply used cat and ssh with time cat test.exe | ssh email@example.com "cat - >> /share/Public/test.exe". The write took more than nine minutes (approximately 1.0 MB/s), and the read (a similar command) was about six and half minutes (approximately 1.5 MB/s). Hopefully a true SFTP daemon would be faster than this method and FTP over SSL. Perhaps not, though, because the power of the 500 MHz SoC is tested by the encryption needed to handle these types of connections.
I didn't see an option for rsync, but when I was messing around inside via ssh, I did see some configuration files. It would be nice to have that available in the administration panel.
The web server on the TS-109 is running Apache 1.3.37 with PHP 5.2.0, SQLite 2.8.7 and MySQL 5.0.27. This box is probably powerful enough to host a very small, low-traffic site, but certainly nothing serious business.
I would have liked to been able to define my own share names, as well as have the multimedia server read from the same folder as everything else is stored in. However, I do realize the purpose of the directory structure of the TS-109 in a business environment.
I also tried plugging in an eSATA external drive. After formatting it, it was available as another share called "eSATA Disk 1" which really should have no spaces in it to keep the Linux folks happy.
Lastly, I tried out the front USB copying feature. I stuck in a 512 MB flash drive. It was mounted as "USB Disk 1"and I tried the copy button. I could tell that the device was copying for a while, then I checked the Public share: nothing. I hopped onto the file manager to search around, and eventually found the copy in the Qusb folder. Neat. However, in order to "safely remove" my flash drive, I have to log into the administration panel and "eject" it. An external button, or the ability to simply yank it, would be nice.