I hate to see I'm everywhere on this forum and don't like to post here, but it's problem on forum - very low activity...
To business:
Yeah. Artefacts in LA have to be well balanced. In CS and CoP artefacts were cheats.
Variations of artefacts in CS and CoP:
1. Radioactive and do other good thing.
2. Antiradioactive and doing nothing else.
It's quite stupid and simple.
I suggest to even upgrade SoC's artefacts properties.
For example, moonlight and soul-like artefacts will affect to satiety (because metabolism is going faster) + do other bad things (more bleeding? Less protection?)
In best - every artefact should have one good thing, one bad (less protection to one of hit types), and one "very bad" - negative effect all the time (more hunger, less stamina, radioactivity etc.)
GSC buried interesting idea of artefact chains - when player need to use few different artefacts to neutralize bad effects of each other.
I hope in LA making chain of artifacts on belt will be real mini-game