Unfortunately better source quality doesn't translate into better images in FS2. Also doesn't USGS map data just cover the USA? Their terrain data is USA only. There's a whole rest of the planet out there, even if some of us are standing upside down.
All your points were stated on my posts.
1. USGS scenery is far superior to free Google and Bing. 2. IPACS may reduce end quality when flying in FS2, but not necessarily. 3. USA only but may include Territories. 4. Users can freely share scenery worldwide when source is included.
Many areas have super high resolution available for airports areas, for instance. This might look great even standing on your head. 😳