In reply to Longsufferingropeholder:
Photo topos are obviously the business for short crags (nearly everything in the UK), but for certain types of route a pictorial diagram is better.
I've found the Rockfax topos for longer (400m+) rock climbs in Chamonix a bit poor. You just can't see enough detail in the features (especially if the photo was taken in sub-optimal light), or the line is so fat relative to the features that it obscures them. If it's a case of following bolts then it doesn't matter, but for traddier routes a simple well-drawn topo with the main features and junctions would be more useful.
Likewise perhaps crags that are obscured by trees, or ones where for whatever reason it isn't possible to get the panoptical viewpoint that the photo shows.