What I'd like would be fully categorised Garmin-style vector data, together with control over which categories were displayed at which zoom levels, and independent control over the zoom ranges at which labels were displayed
Sort of like:
Class | On | Min | Max | labels | Min | Max |
A road | On | 0 | 20km | off | 0 | 2km |
B road | On | 0 | 5km | off | 0 | 800m |
tertiary | On | 0 | 3km | off | 0 | 500m |
unclassified | On | 0 | 2km | off | 0 | 300m |
residential | On | 0 | 1km | on | 0 | 200m |
50m contours | On | 0 | 5km | off | 0 | 1km |
10m contours | Off | 0 | 3km | off | 0 | 500m |
rivers | On | 0 | 5km | off | 0 | 500m |
streams | Off | 0 | 3km | off | 0 | 500m |
towns | Off | 0 | 3km | on | 2km | 5km |
villages | Off | 0 | 3km | on | 1km | 2km |
pubs | On | 0 | 2km | off | 0 | 500m |
cafes | Off | 0 | 2km | off | 0 | 500m |
supermarkets | Off | 0 | 2km | off | 0 | 500m |
It would also be nice to pick symbols, line colours and thicknesses too.
You'd spend the first couple of weeks fiddling to get a setup you liked, and then just turn extras on (eg campsites) as you wanted them. With a decent set of defaults many people wouldn't need to fiddle at all.
Raster data like OS 1:50,000 looks nice, but it's only good when displayed close to the intended scale. If you want a different scale, you've got to store a complete separate set of data.
So UK 1:250,000 data in my MemoryMap folder is 138 MB
1:50,000 data is 25 times that at 3.1GB (coverage doesn't exactly match due to missing sea)
1:25,000 data is 4 times at 12GB
1:10,000 data is 6.25 times at 75GB (looks like
this)
1:2,500 data would be 16 times at 1.2TB (if it was available). (fully accurate at this stage)
You would need to go down to at least a 10,000 scale to compete with the accuracy of the Garmin vector data.
The really big drawback is that you can't turn different parts on and off separately, so you don't get the roads without also getting all the buildings and garden fences, you can't turn round the text etc.