Hi All,
I am here quite a bit these days!
Here is what virtual stations do:
Check this to have ASX automatically generate stations within FSX in order to fill gaps and provide more weather coverage. Stations are generated at approximately 100nm intervals and inherit and/or interpolate the weather of nearby reporting stations. When using this feature, FSX should be closed before ASX in order to prevent a delay that occurs when FSX needs to remove Active Sky's generated stations on disconnect. Note that the use of virtual stations within FSX can cause a performance hit as well as potential wind shifts in some situations which can cause problems with certain add-on aircraft.*
*Note: Due to some inherent FSX interpolation issues, wind shifts can be experienced at any altitude with any option configuration but can be minimized depending on your altitudes and area of flight. Some experimentation of the Virtual Station and Route Coverage options are recommended to find the best balance of resolution, coverage and smoothness.