I read this before I arrived in Taiwan back in the summer of 2010. I had bought it, because I had previously read "Culture Shock: Cuba" for one of my university courses and had found it very enlightening. I never went to Cuba, but I bought "CCT" to prepare myself for moving to Taiwan, for what was at the outset to be for the duration of only one year.
Now it's my third year in Taiwan. Furthermore, I married a Taiwanese man and now call Taipei home. I wouldn't accredit that course of events to anything I learned from this book, but this book is very useful.
It had been sitting on a shelf in my apartment for the past couple of years, and I recently picked it up, blew the dust off and began to re-read some sections. From my current point of view, I can endorse much of what the author discusses in relation to culture in Taiwan with confidence. However, it's necessary to point out that some of the things he mentions (like a Taiwanese boy child ripping out a wad of his blonde arm hair during a martial arts clinic in Taichung) would never happen in contemporary Taiwan, 2013.
But, much of what the author says about religion, customs, etiquette, still holds true. The section that talks about gift giving is particularly useful. Ie; giving gift money as per custom at weddings, how much one ought to give, and taboo number amounts (multiples of "4").
My only complaint is that he uses a very strange Chinese romanization style, which is not the same one that readers will see once they actually are in Taiwan. Ie; he spells xie xie (thank you) "sye sye." Not only is this form of romanization obscure and confusing, but it's also difficult to figure out how to pronounce. Hanyu Pinyin is much more straightforward!