There are mainly five runewords that you can do with staves
1) Insight (4sox)
> Usually not so needed but with the new warlock insight is now one of the best weapon for him so a eth elite insight (elder staff, archon staff) will have very high damage
> Can also be used by sorc for lld or other type as a starting ladder weapon
2) Obsession (6sox)
> Very good for sorc a good base is usually +3 to a main skills (fire ball, nova, blizzard, lightning...), a very good base has also +X to the mastery (3fire ball 3fire mastery worth about 2000-2500)
> Now with warlock that can one-hand staves, any random obsession is very good for them
3) Memory (4sox)
> Only good for sorc with a 3es staff, good adds might be one of the cold armors, enchant...
4) BotD (6sox)
> Eth archon staves have huge damage so they are a good base for botd, before it was mainly for fury druids now very décent also for warlock
5) CTA (5sox)
> As a prebuff weapon it's good with prebuff skills (3es, cold armors, enchant...)
thank you, this really helps me understand it
thank you also to all others that responded and also helped illuminate things