I'm quite shocked that this ccTLD is flying under the radar. Did a quick background check and yes the number systems are pretty much identical. Yes I understand Taiwan and China are different countries, but share many similarities, and of course business too. So If you are a strong believer in numbered domains for China, then a N.TW might be something to acquire as well. I picked up 5 NNNN.TW because everything from 1 to 1000 and even the 0 starters are gone. I believe this has a good chance of picking up next year and 4N.TW, possibly 5N.TW getting taken too. Below is an interesting link I found.
http://www.expatintaiwan.net/numbers/
http://www.expatintaiwan.net/numbers/