Hi Franco,

I have ideas, but not much I'd call knowledge:

1) The resolution given in the style determines how detailed lines or polygons are saved (e.g. the DouglasPeuckerFilter removes more details for lower resolution, other filters may remove
too small objects)
2) The levels give the "internal" structure of the map. One or more resolutions are combined in one level, a map has up to 8 levels.

I have no knowlledge how the device decides which resolution it has to read from the img file when a specific zoom is needed. I guess this
may depend on the device.
I guess that MapSource / Basecamp show the same amount of details as a device with the "normal" map-detail setting. Higher values probably
mean that MapSource reads the details from higher resolutions as well.

Gerd