Tbh I would prefer a system where the blend of powerful unique items can be found at whatever level however it might be limited to ammo or might be hard to get ! If you give the player character a power wep but make it hard to get either through dialogue or quest this is much more rewarding for the player. Crni you would be right about the power Armour thing however I don't actually think power Armour re spawns in fallout 4. But I think your right about getting the right blend.
I think legendary items was a nice idea however for a fallout game I think its bit to showy. It can massive OP the player if they get the right legendary early even though there is safe guards against that. It also penalizes players who play at low difficulty's as they have less chance to find legendary items. They system also makes weapons you get from quest less meaningful as you can already get OP wepons for killing one monster. Atleast getting high level weapons in other fallout games where you add to clear out an area of high level enemys just for one gun rather than just kill one legendary
I think legendary items was a nice idea however for a fallout game I think its bit to showy. It can massive OP the player if they get the right legendary early even though there is safe guards against that. It also penalizes players who play at low difficulty's as they have less chance to find legendary items. They system also makes weapons you get from quest less meaningful as you can already get OP wepons for killing one monster. Atleast getting high level weapons in other fallout games where you add to clear out an area of high level enemys just for one gun rather than just kill one legendary