Gould, Kitcher, Gardner, and others have all argued against any single generalized factor of intelligence g or "IQ." I agree that a scalar g or IQ may not be able to represent what we mean when we talk about intelligence. I believe a vector may be needed, consisting of components like:
memory (amount, accuracy, etc.)
speed (of recall, of deduction, of saving to memory, etc.)
These components of a vector intelligence measure are NOT assumed to be orthogonal.