How effective are they? Can they be used at high levels, against draugr deathlords etc?

An example, the expert spells 'circle of protection' and 'turn greater undead', the first affects level 20 (so level 44 dual casted) and the second affects level 21 (level 46 dual casted). Do people use these spells, or perhaps the master spells at high levels?

I am wondering the same thing with the conjuratuon perk "oblivion binding". It is supposed to banish summoned critters and turn undead.

However, when I hit summoned & undead creatures with my bound bow they take damage. I have never seen what I would interpret as either effect.