OP: Back on topic to your question about TPES:
DS taught self to read at age 4 and was reading 2nd grade books and ahead in math as well (as shown first by playing Monopoly games where he'd mentally keep track of everyone's money through the whole game

I don't think of him as exceptional -- he simply has what I call younger brother syndrome ("I can -- and will -- do anything big brother does.")
We found home school lacked peers for him. The approach there was that the other kids would catch him. He knew that he was ahead of the other kids, so it was just a bad situation all around.
TPES was a godsend for us b/c he's not DIFFERENT there. Same curriculum, but more differentiation and more kids doing more advanced work. We also are close geographically, so the commute isn't a big deal. We see a definite difference in writing expectations from our home school and TPES.
You'll need to decide for yourself whether your home school is working for your child.
RE: some of the discussion about kids being fine in a regular classroom even if they are ahead. We thought that of our older child. He didn't complain. He did all that his teachers asked. A model student. It wasn't until he switched schools to one where he was more challenged that we learned a few things:
1. He TOLD us after a couple of months in new school that he loved FINALLY learning something in math. He didn't feel like he learned anything the previous year.
2. A teacher this year has had to teach him and others in his class real learning habits. For instance, the kids would not be as careful as they needed to be on math questions because they were so used to not reading questions and going down to a line and answering. The kids had to learn the hard way to READ the full question and show their work. Apparently, according to teacher, this is a common issue with kids who have been bored. They learn they don't have to do all the steps to get the right answer.
Thank goodness for some good teachers and good schools who are willing to step in and deal with kids who simply need more, faster than the curriculum is willing to give.