Do Immediate Reactions that trigger on hit trigger before or after you take damage?

Question

I've seen a lot of different opinions on the topic, so I'm not really sure how it goes anymore.

If you have an immediate reaction on hit, do you take the damage before you react? Some say yes, because the action has to be resolved, meaning the whole attack has to happen, and others say no, because what is the point of a reaction then, and that the action is resolved in that the attack roll is over.

For example, avenger's level 2 utility prayer Resonant Escape:

Immediate Reaction; Personal
Trigger: An enemy hits or misses you with a melee attack
Effect: You teleport 3 squares.

Does one teleport before or after taking damage?

Answer 1

The definition of an immediate reaction (PBH pg 268):

An immediate reaction lets you act in response to a trigger. The triggering action, event, or condition occurs and is completely resolved before you take your reaction, except that you can interrupt a creature's movement. If a creature triggers your immediate reaction while moving (by coming into range, for example), you take your action before the creature finishes moving but after it has moved at least 1 square.

Mechanically speaking, the attack action would resolve completely and you would take damage THEN you would take the immediate reaction. In your example you would take damage then teleport.

There is really no ambiguity in the RAW on this topic, regardless of people saying that this makes the reactions useless, you cannot deny that the rules say that the action fully resolves. However, in reality, it does not make these powers worthless, because you still get an additional action on your turn.