The BGS manuals and CD-ROM complement each other very nicely. The manuals are ideal for reading on the train to work, while the CD-ROM’s animations are particularly useful (I was even starting to understood gyros once I’d watched the movie a few times).
The CD-ROM’s facility for instant marking is also extremely useful. In short, I work from the manuals and use the CD for tests, or for when I’m struggling with a particular subject – very flexible indeed.