I would suggest you read 'misdiagnosis and dual diagnosis of gifted children'. It won't really help, but it will crystallise your thoughts! 
Your Ds sounds like mine.
Did they do a full psycho-ed evaluation, or just wechsler/ wiat? Did they look for co-morbids, or just ignore the issue because he reacts well to 1-1?
Was his wechsler testing 99th across the board? Or was he 99.9th in half of the test, and around average on others? Spiky results? Which still meant gifted overall, but lower in, for example, working memory or processing, and high in verbal reasoning etc?
No one bothered to dx Ds until y5, tbh. We always accepted he was quirky and impossible to motivate unless his interest was piqued, in which case he was unstoppable. Because he was obviously bright and brilliant 1-1 (but crap at random boring staying on task in uninteresting class work) every school he was in let it slide, as they knew he was bright enough to keep up.
Over the years, people have suggested pretty much every sn known to man, as well as 'just gifted'. I still don't know, really, he's still just Ds, but a full pyscho- ed eval just before his tenth birthday said gifted with ADHD with aspergers traits and anxieties and phobias (he also has continence issues as he just won't/ can't be bothered to stop what he is doing and get himself to the washroom. This is possibly explained by the hyper focus aspects of ADHD, or whatever they call hyper focus in gifted kids.... Ummmmm, forgotten!)
So, I'm still not completely convinced, but it means that yes, he's bright, and yes, he has quirks....
Gifted kids can have aspergers. Gifted kids can be nt. sometimes gifted looks like aspergers. Sometimes kids with aspergers are not gifted... Sensory difficulties can be explained by ASD, or by overexcitabilities in gifted kids... There is a lot of overlap, and it is very difficult to unpick!
I have absolutely no idea whether this is remotely useful, but I would deffo the read the book I mentioned before I went all stream of consciousness on you. 