Jamie, I used to make my own butter all the time. I still do on occasion but I am old and lazy now.
I use nonpasteurized, nonhomogenized heavy cream straight from the farm from a cow that was milked just a few hours earlier. Yeah, I can hear the sighs and moans now. Nonpasteurized! Good heavens! Been drinking it for eons and somehow never died.
Anyhow, the heavy cream straight from the farm is soooooooooo much thicker and richer than anything I have seen in a store. It whips into heavenly cream very fast and into butter almost as quickly. Nothing in the world tastes as wonderful!