I don't have any great advice for you but this thread has brought up some interesting thoughts for me to ponder. The schools so often focus on and offer math acceleration *partly* (I think) because it's so quantifiable - easy to see move from pre-algebra to algebra to geometry etc. Each class through HS somewhat follows the next. While our ds is really really talented at math (or so his teachers tell us), and while he likes it, science is his passion. I've always seen math acceleration as the path to allowing him to take science classes at his ability level early. I'll be honest, I have no clue what we're going to do for high school (he's in 7th grade) but I've always seen dual-enrollment as the most likely path he'll follow.
I don't really think (again jmo) that worrying about maturity re understanding how math concepts apply is a reason to not take algebra early - please understand, I have a degree in math, so I know something about it lol. I remember geometry really bringing connections for me, and then calculus as the place where the real world connections started coming together in an exciting way for me (geez, I sound like a nerd lol). I don't remember much about my algebra 1 experience other than where I sat in class and my teacher making fun of my school picture.. and it didn't ruin math for me or change the direction of my life in any meaningful way.
The one thing I'd consider here in this case is the loss of the elective choice - depending on the child. That would be huge for my ds - he lives for his electives even when everything else is working great in school. But otoh he's a kid who needs that other type of whatever-it-is that he gets through extra art and things like that.
polarbear
