I had the same experience. They separated us "gifted" kids very early on.

I had no negative experiences other than being a bit out of touch with the culture of my area, which isn't necessarily a bad thing either.

I had mostly ok teachers and no problems learning or making friends. I recall there actually being a lot of free time to just study whatever we wanted most days. We never struggled on the mandatory standardized tests, so the system left us alone. It was very uneventful and boring.