Tigerle, we didn't accelerate even though our ds has been working way ahead of grade level since he was very young. Have I ever had regrets? Yes. I've also had many times that I've been thankful that we didn't. I think that truthfully there is no clear answer in either direction for most kids, and no crystal ball for us as parents to look into and know what the best answer will be for "most of the time".
All in all, accelerated or not, I think the key to success for all of our kids is staying in touch and involved as a parent and being flexible enough to change direction or forge a new path as your child encounters a new bump in the road or a new opportunity along their journey.
For us personally, the one large looming thing that held us back from accelerating was hearing from parents of children who had been accelerated that it was great for elementary school but they regretted it once their child was in class with middle school kids going through puberty. I also honestly didn't want to lose any years that my ds would be at home with family by sending him off and away to college at an early age. For our ds, that decision worked out well because he's always been happy being with age-peers and once he was mature enough to talk about this and give us his opinions, he was very clear that he also didn't want to be whole-grade accelerated. He's also very clear with us that there have been times that boredom with the pace and intellectual level of some of his classes has been beyond bearable - but he would rather have that than be navigating socially in a grade where he was by far the youngest student. Did not accelerating prevent him from learning at as high of a level as he is capable of? Definitely at times, more so in his early education than now in high school, but yes, it did. Did it matter? It felt like it did sometimes back then, today I'd say a big "NO". He did not become lazy and he didn't lose any of his love and motivation for learning. He may have added a few years to the time it will take him to find whatever career he ultimately decides, but that's ok. Really.
So sorry - no real advice here, just a note that it's sooooo not ever going to be easy to know which is *the* way to go. And there might be multiple ways to go! The best any of us can do as parents is to gather all the input we can, and then go with whatever our gut feeling is - so trust your instincts, whatever direction they are pointing
Best wishes,
polarbear
