I only use butter (just regular unsalted - not clarified) when cooking eggs. While I do use oils & oil sprays for other applications (the outdoor charcoal grill, certain baking pans & dishes, etc.), I just don't care for them when it comes to cooking eggs - omelettes in particular. They never release from the pan as easily with oils as they do with butter - at least for me - & I don't care for the flavor. And you don't need an awful lot of butter to get the job done. :)
The best eggs I ever had were served up in NE PA. Little local dinner (might have been an "Amish" place). They came out in their own cast iron pan, swimming in butter. I have considered the 5 hour drive just to have them make 'em again, though I suspect the hype would make them not as good.
"First you start with a pound of bologna..."
-My Grandmother on how to make ham salad.