I don't think it is necessarily a gifted thing. Some people here and elsewhere report that their kids can spell well off the bat, due to recall-- this may be linked with the way many gifted kids learn to read, by memorizing whole words, although it would take closer to perfect recall to not only identify known words but be able to also recall the spelling.
My son is verbally as well as visually-spatially advanced and doesn't seem to have much trouble spelling, although he doesn't have instant recall of every last word he's glanced at. But he seems to have a good handle on phonetic rules in English, which is bound to help in encoding as well as decoding. DS5 has plenty of frustrations in output right now, but mostly with slowness of writing and typing, etc.
I guess some gifted kids might be slower to spell if they can't remember the exact spelling for a word easily, are whole-word memorizers by nature nonetheless, and haven't internalized many of the encoding rules so can't get help there. I can see how that could get frustrating, and fast.
