I just got this mapping, since it was on special, and should give more detail for me when I'm route finding around London.
When I use my 1:50000 mapping, it switches from the lower resolution raster mapping to the 1:50000 mapping at around 1:55000 and shows that at various scales until I get to about 1:6500, at which point it switches to the base vector mapping.
With the A to Z, which is at 1:14000, you get the vector base mapping as you zoom in, until you get to about 1:21000 when it starts to show the A-Z, and zooms in until you hit the most zoomed in at 1:1000, when it's far too zoomed in to actually see much.
I've photographed a couple of locations with the same level of zoom, and an identical location. I found out that you can change the maps on the fly, and when you insert a new map, it will display the same location, at the same zoom level (if it's capable of doing this, obviously).
You do get quite a bit more detail on the A-Z mapping, I also noticed on the first set of images, where there is some track visible, that the track is pretty accurately running along the road I was on (although around the corner, the GPS fix went a bit loopy). With the 1:50000 mapping, the track doesn't appear to be on a road, and indeed, the nearest road
wasn't the one I was one, so the alignment between the GPS and the mapping is better on the A-Z.
To be fair, on the latter point, most of this mapping was never originally intended to be used with devices capable of providing geographic fixes this accurately. The fact that it works so well is quite impressive.
