Not consistently, but I've been GMing at some point or other pretty much since I've been gaming, so somewhere around 20-25 years, I guess. I think I'm a decent GM, but I've come to recognize some of my limitations, too. I'm not the kind of GM who can make a great game out of any system or any setting. It has to be one that I really connect with on some level.
That may be why I prefer to homebrew.