The Koran is a classic of Arabic prose and poetry and a key religious text. However, it has yet to be introduced to the West in an accessible and accurate way (at least on a large scale). This translation does some of the work. It was made I believe in the 1930's, so some of the language is a bit archaic today. Nevertheless, it often employs good expression. The author himself admits his work is a poor echo of the original.
The book is typeset like poetry, with various changes of tone indicated by changing the layout from a more prose-like one to one with more narrow stanzas. There is also much white space. This is a very positive point as most texts, especially translations, ignore white space as a crucial feature in understanding.
A noticable defect is the total lack of commentary. Unlike other religious texts, the Koran is structured around a context that isn't present in the text (whereas say the Bible provides many historical accounts, as opposed to just reflections on them without the stories). The Suras are arranged roughly in descending order of length, not by topic or time. As a result, reading from cover to cover, you jump around in time and place hundreds of times, so a bare, unannotated translation means a lot will be missed. Even a simple introduction to each of the 114 Suras would have done well, but alas.
A good bottom-line version for those who aren't Muslim and want to read the Koran from a secular point of view, but don't have time to get into the details. If you want anything more, look for another translation.