Expressions like intentionality or prehension which purport to point to the atom of consciousness may be flawed but at least retain the quality of implicit action, especially the latter. Qualia on the other hand is explicitly passive and so lead to an infinite regress of observers, or you could say the qualia of each quale. How do you recognise a quale? By its distinctive qualities etc. Qualia appear to be more scientific because they are theoretically, and perhaps practically measurable because they fall short of the active experiencing. Intentionality and prehension are not measurable, the mystery of consciousness is not solved but simply taken as given, or postulated. The 'I' with its dual nature is in the activity. From the qualia point of view there is no 'I' - this may suit ideas on non-self, or anatman, but foreclose experiencing.