Synaptic storm, I think Dabrowski's overexcitabilities are real - but that they are a great big distraction that stand in the way of many gifted kids who really are 2e getting the help they need. The first question is whether the child's environment is appropriate, if its not, you can't blame the child for not coping. If the environment is reasonable then the next question is - are the "over excitabilities" impairing the child's functioning/daily life? If not, then yes you have over excitablities. If they are crossing the line into making life really difficult for the child then you need to consider that the child is not completely neurotypical.
I do know a lot of highly gifted kids who are 2e. Mine are. But I think this is in part because people seek help when their child is either way off the curve or has problems - either the problems that are directly bothering the child/parent, or the parent can't figure out why school doesn't "get" their kid. People seek support groups like this because of exceptionality...
In my own family my child with Aspergers, sensory issues, CAPD, dyslexia, and more is my child with the lowest IQ. She's MG at best. My HG+ child does have ADHD, but she's way, WAY less 2e than her sister (more gifted, less neurologically atypical). My youngest child is not yet tested, so far she has some significant physical health issues but developmentally she's looking likely to be at least HG+ and not likely to have ADHD, she absolutely is not on the spectrum. So in our family the most neurologically atypical is also least gifted, and the one that looks likely to be most gifted also looks likely to be most neurotypical.
The most gifted child I know personally is neurotypical but clearly does have over excitabilities. Most of the very gifted children I know personally, if they are also neurologically atypical are not dramatically so, with adequate support (and for most it truly is is more about good support than major intervention) they'll grow up to be seen as no more than quirky.
