Similar situation, but my kid is one year ahead of yours. He turned 5 in August & started kindergarten.
Last year near the end of pre-K, the teachers and principal had a meeting w. my husband and I because my son was having a hard time staying focused on stuff he thought was boring, working independently on things that seemd pointless to him. ("Gosh, I have *no* idea where he could've gotten that from." sarcasm). I think they said he was having "difficulties internalizing classroom expectations." One teacher even said I needed to lecture him on the importance of keeping his "nose to the grindstone." I mean, for Pete's sake, he was 4! How many 4 year olds have a strong work ethic, especially when no one has gone to much effort to make the work interesting or explained how it's at all relevant to him. He just saw it as grown-ups being bossy for no reason. I interpreted it more as "has difficulties pretending to be interested when he's bored out of his mind." Of course he's more interested in playing - that was fine with me. I've studied enough about early childhood development to know that's how kids learn best at this age anyway.
So I suggested holding him back in pre-K. He was only getting 3 hours a day, 3 days a week and next year he could go to pre-K full time. Besides, his two best friends, born just a few weeks later, over the "cut-off" date, wouldn't be starting until the 2009/10 school year.
And, the biggest kicker for me, I would get him one more year around 17-18 before he went off to college (I hope) and gets exposed to... well, all the stuff *I* was exposed to in college. YIKES!!
But the principal said "Nooooo, he'll be bored!" The two pre-K teachers said "Nooooo, he's a smart cookie, we don't want to do that!" My husband said "Nooooo" but I can't remember what his dopey reason was. :) And I have a very strong suspicion that the principal had already made decisions about the classroom capacities and holding him back would create a vacancy that she would want to fill. (It's an independent school) They did have a point. I'm not gonna get all smarmy and go on about how brilliant and gifted my kid is... but i'll say this - he's NOBODY'S fool. Let's just say that no one thought the problem was intelligence or learning abilities.)
Bottom line is, there was some doubt, but he progressed to kindergarten. And now there are problems. Yeah, he's still plenty smart enough, but he doesn't have the self-control they expect, he giggles when he's not supposed to, he hums when he's not supposed to, etc. Nothing mean-spirited, he's very kind and gets along well and doesn't throw fits. I talked to the school counselor and she said that it's just basic maturity. You can teach a kid a specific skill early, like reading, but it's really hard to teach them to act older than they are, and what's the point really, when it *does* some naturally with time? I'm simplifying this some, we *are* working on self-control and started him in a kids' Aikido class, but the bottom line is that the best way to deal with this is to take off the pressure.
We pushed him before he was ready in ALL aspects, (again, his "academics" were fine, emotionally he was fine), and now he's having a bad experience in kindergarten because he's suddenly the "troublemaker." He's failing not because he isn't trying hard enough, his current teachers TELL me he seems to be trying, but because the adults around him made the wrong decision and put him in a situation where the expectations are just out of his reach. So now that he's had his first bitter taste of failure and had his confidence shaken,
we're going to repeat kindergarten, and I kick myself every day for not doing this last year, when he could have had another great year of preschool, and had lot more self-esteem.
So here's my take on it. If you're going to repeat, the sooner the better. Pre-K is better than kindergarten, and kindergarten is better than the "grades." Once they are in "Grade 1" they expect "grade 2" then "grade 3" etc. A lot of folks push to get their kid in kindergarten, but then find that every year is a struggle to keep up. (Or worse, the kids have to reapeat 3rd grade and there's soooooo much more stigma. Or even worse than *that*, they may develop those mysterious stomach ailments, or other problems that are stress-related but they just don't understand that or know how to cope with it.)
So many things will take care of themselves when you give a child "the gift of time." What's the rush? The stress of homework and tests will come plenty soon enough. Preschool is a pretty golden time to just enjoy being a kid. And that extra year at 18 will hopefully give them a little more wisdom and judgement before they're on thier own.
good luck!