He was in public school through second grade. Kindergarten and 1st grade were great. He had awesome teachers. In the 2nd grade he ended up with a teacher in poor health that probably should have retired 5 years prior. It was not a great year and my wife had always wanted to try to homeschool but I was skeptical. So in 3rd grade he stayed at home.
Overall it went pretty well. There are tons of resources available to help however you must pay attention. My wife wanted to send our son to this 2 hour "science club" thing that met a couple of times a week. At first glance it sounded great until I read through all the literature. Turns out the guy taught Intelligent Design. I just about lost it. Some other home schoolers had recommended him to my wife. People homeschool for a variety of reasons but for a fair number it's because they don't like what is taught in public schools. I'm a fairly liberal guy. Hanging around that crowd was a tough thing for me at times and it was a source of tension between my wife and I.
My son is a social kid and he wanted to go back to school after a year. So for 4th grade, we found a private school with a small class size that seemed like a good fit. He was there through 8th grade but we often questioned whether it was worth the money, - especially once he got to middle school. From a math and science perspective he probably would have been better off in a public school.
We have neighbors with a large family that also homeschool. Once the oldest got to be about 12, he wanted to go to a school and the rest of them kind of followed suit once they got older. They're great kids. We know other families too where the results have definitely been more of a mixed bag. With one family in particular the kids are very accomplished in some areas while severely lacking in others, but that may have happened no matter where they went to school.
My take away from all of this is that success can be had in public, private, or home schools but it depends on the schools, the parents, and most of all the kid.