Long Range Scanners

[Captain Kwok]

They provide you information regarding other ship designs and their cargo contents up to the distance in sectors specified - provided that the ship does not have scattering armor or scanner jammers.

[Fyron]

At least for PBW, the ubiquity of scattering armor makes long range scanners less than useful. The defense bonus of the armor is crucial, and the scanner blocking is just icing on the cake.

[Arkcon]

Most of the TDM modpack races research scattering armor early as well. In the standard game, AI races may take a while to research it, but once they have, they start using it.

Still, an enemy ship returning from a battle you didn't take part in may have been stripped of its armor, and you can glean a ship design to see what you'll be up against. Its fun to have, but I wouldn't make it a priority research.