I used this map to walk up Ben Nevis via the Carn Mor Dearg arete route.
Good points: clear and uncluttered. As well as the map of the area in 1:25000 scale, it has a useful close-up of Ben Nevis itself in 1:12500 which clearly marks where the dangerous cliffs are, and gives you the compass bearings for walking off the summit in a whiteout.
Could be improved: a bit TOO simple in places which could do with more detail. e.g. the steep slope due south of the summit is depicted simply as 'rocky ground / scattered rock and boulders', which is what you'd expect on a mountain. In fact it's really loose rock, quite treacherous with a risk of triggering serious rockfall, which isn't apparent from the map. The OS map gives a better impression of what the terrain is actually like.
If I was going back to Ben Nevis I would take this map for its good points, BUT I would check my route against the OS map first and make a note of any extra detail. I might take the OS with me too as a back-up.