For example, the word used for a high lama's doorway is different from the word used for your own doorway. This takes some getting used to. There is also a system called Wylie for representing Tibetan characters in English. This is useful if you have to send an email about a Tibetan text. Lhasa dialect, including some grammatical forms which are only used in Lhasa spoken Tibetan.
Tapes are very good quality, compared to the other tapes which are available.
It took me about 4 months to go through the whole set. Includes several passages which are translations of Chinese Communist party documents into Tibetan. I do not see the value of these, unless you wish to see the Tibetan language struggling to evolve phrases for modern Communist party terminology. I have not found this a particularly useful book because some of the explanations of Tibetan grammar are themselves so complex, I get lost. On the other hand, it explains Buddhist Tibetan vocabulary very well.