I agree that 40 series are old-tech, but when working properly, drums work just fine. While they do need adjustment from time to time, shoes last twice as long as pads in my experience. I have personally experienced fade from overheated disk brakes too, anyone who says that disk brakes can't fade from heat just hasn't had to be strapped down to Slickrock Campground from Sand Creek Recreation area with no driveshafts :-)
I have also pleasantly been surprised that the drums on my 71 work fine after water crossings, including the south Platte going from Hackett Gulch to Longwater. For whatever reason, the drums in my 78 aren't as tolerant of water.
I hate adjusting drum brakes as much as the next person, but I'm a fan of "if it works leave it alone", I've got enough projects!