Legions Heavy replaces the standard 256x256 resolution Legions textures with 1024x1024 normal and diffuse textures and 512x512 - 1024x1024 detail map textures, resulting in generally nicer looking terrain and objects. This HD texture pack is not complete, but in its current state it replaces a more than moderate number of terrain and building/object textures.
How much will using Legions Heavy impact my performance?:
To be honest I don't have any solid data here. I would imagine that this wouldn't have much of an effect on game performance for the vast majority of modern computers. On my computer I never dip below 60+ fps with or without Legions Heavy (8GB RAM / NVIDIA GeForce GT 230).
Other Information and Important Sidenotes:
1) All textures used in Legions Heavy are edited textures originating from CGTextures.
2) All texture editing was done using The GIMP.
3) Textures of greater complexity than standard tileable ones are created using The GIMP and Blender.
4) Legions Heavy is so-named because it is in several regards the opposite of Mornaval's lag-reduction project, Legions Lite, which increases frame-rate drastically at the cost of aesthetics.
Installation Instructions:
1) Extract the contents of the downloaded RAR file into your Legions: Overdrive directory.
2) Make sure you set your entire data directory to read-only ([Legions Directory] > Live > Legions > Data).
3) If further help is needed, ask a question below or see ColoredSpades' Guide to Installing Modifications.