Sounds very familiar. DD now almost 9 didn't fit school from the beginning and it showed. She is grade skipped, still at the top of the class, actually having to exert the tiniest bit of effort, struggling with OEs and perfectionism and overall, still not a good fit. Even with the advocacy and the improvements, she has pretty much turned off to learning - the demands weren't getting met and she is now mostly just going through the motions - no longer actually all that interested in school or learning. Since the grades aren't suffering, school doesn't notice (although the gifted teacher is starting to).
In my opinion, DS 6 is likely higher IQ (more likely DYS in my opinion), but doesn't show it the same way. He is clearly less verbal, more visual-spatial, problem-solving, but he came with a happy-go-lucky, 'life is good' personality. I remember him playing quietly by himself in his room with his cars and toys for 30-45 minutes or more at the age of 2, while my then DD5 still required attention and interaction at five-minute intervals. The personalities are just different. Even though I believe that DS6 is likely a higher IQ than DD8, at this moment in time I believe that a relatively normal school program is likely to work for him, just because of who he is.
DD demands to be led and taught and and needs to be nurtured and encouraged. DS only needs to be let off the leash and he will take care of the rest. We'll see how that continues to play out as we proceed through the early elementary years.
If there's a reason to retest then consider it - we did and I'm very glad we did. I thought my DD's RIAS was flat wrong and although it gained her admission to the gifted program, I was pretty sure that was not going to be enough. I also had that little doubt that I had misjudged and perhaps she really was DYS, so we shelled out the money to have the WISC and achievement testing done. In fact that testing confirmed what I thought I knew all along - not quite DYS, but outside the 'garden-variety gifted' box. Besides now we have a relationship established with a local tester and now that some other things are cropping up, I have that resource.
If you have no immediate need to retest, that's OK too. But if you decide to do some sort of talent search or acheivement testing and it looks out of whack with the data you've already got, maybe then you retest. We did SCAT in 3rd grade (first year accelerated) and those scores continued to back up what we already had - missed the CTY cutoffs by 1 point each in verbal and math which put her right at 95% for her accelerated grade. If she had blown the SCAT away, I might have thought long and hard about whether we needed to revisit earlier scores or do something different.
Good luck!
