This will improve your shadows, increase your frame rate, and remove shadow striping. Shadow quality stays at an 'Ultra' setting equivalent, while providing a frame rate faster than 'Low' setting shadows, not to mention the shadow striping being fixed.
If you absolutely, positively need a reliable companion then you want Haez. She is deadly, has a multi-faceted spell list, and carries the "Fanged Katana." The best spellsword in Skyrim. She also carries a torch, a bow, and has her own set of Glass Armor. [Standalone Modification]