Oh-- what I do think may be important to appearing gifted is the rate and ease of transition from short-term to long-term memory. Again, using myself as an example, I remember numbers which I use frequently. I have to work to put them into long-term memory, in other words.
Words, though? Not-so-much. Thus my spelling ability.
But my working memory for letters isn't that fabulous. Probably about average, I would guess. A string of characters and my span is about 7-9. That's better, note, than my digit span.
But nowhere near what it is for a WORD task of similar nature. I also have better short-term recall of musical notes, spatial information (yes, I was quite good at memorizing/manipulating information in advanced organic chemistry and instrumental analysis), or color.
I think that any single type of evaluation of WM is probably flawed in that it unfairly evaluates some people on the basis of an area of strength (I'd look... probably off the charts at a COLOR task... and most people wouldn't)... and others on the basis of an area of relative weakness (me with digits) due to differences in the nature of the information in the task.
Not all visual, auditory, or sensory information is processed using the same "intake" centers in the brain. I don't think that there is just one type of "working memory" in the first place.
