I've decided that the Thecus n2100 is not worth the effort. While I had fun and learned a lot in setting up Debian on it, it has consumed a lot of time. In my humble opinion, the device does not perform well enough to merit its expense as a NAS.
If I were to do it over again, I would instead choose the Buffalo Linkstation Pro, which has an aggressive price (around $170), includes a drive, outperforms the Thecus, and is smaller. The Linkstation Pro also runs Debian!
The Thecus n2100 costs $290 without a drive! Considering I just bought a notebook with 512mb of ram, a 60gb hd, and a much more powerful processor from Walmart for $108 more ($398) , its ludicrious to pay that amount for the Thecus. Thankfully, my Thecus at least came with a 256MB ram chip i can re-use as well as taught me a little about serial connections.
Lingering Questions
Is there a quality NAS that has a reliable serial connection? While I'm very glad that the Thecus n2100 had a serial connection, it was really difficult to access, requiring the removal and replacement of the hard drive chassis. According to this page on adding a serial connection to the Thecus n2100 , the later boards don't even come with the pin-outs! What's worse, I could not get a consistent read on the serial connection from the Thecus. I tried a real null modem db9 serial cable, but since it didn't work, I ended up using simple wires to make the serial connection to the Thecus.
The Buffalo Linkstation doesn't have a built-in standard serial pinout, nor does the NSLU2. Do any of these work with a USB2Serial adapter? Not likely. Alternatives
Instead of a Thecus n2100, why not buy a Shuttle PC? This link to newegg.com offers a barebones for $179, plus $75 for a processor, and you've got yourself a MUCH more powerful machine than a Thecus n2100, for a cheaper price!
I'm actually thinking of building a high performance RAID0 NAS out of one of these. I'd get another nic card (four port would be good), ram, and a dual core processor. For a few dollars more than a Thecus, this machine would scream. Question: how much energy would this consume?