Quote Originally Posted by impulse View Post
Эта книга трудна для перевода VS Эту книгу трудно переводить
It's all about variations in Russian. In Russian there can be different ways of expressing approximately the same ideas. In short, a speaker of Russian has a choice as to what to say and how to say it (such variations make the language more versatile in terms of language aesthetics and expressive ability of the language; as a natural consequence, the language becomes more complicated in terms of studying and understanding if you are a foreigner having mis/fortune to learn Russian).

So Эта книга трудна для перевода ~ This book is difficult to translate. (in Russian it's emphasized that the book itself is difficult to translate)
 Эту книгу трудно переводить ~ It is difficult to translate this book. (in Russian it's emphasized that the process of translating is difficult).... seems the meaning is very close and the difference is very subtle

In English such variation is possible due to change of word order, because this is the nature of English, it's how it is organized.
On the contrary, in Russian, change of word order can be used to emphasize certain words in the whole sentence, PLUS Russian has this ability to use other parts of speech (short forms of adjectives, using verbs if deemed better).

I think in this choice of words in Russian it's all about the speaker's choice and what they want to emphasize, how they want it to sound.