I have been running ceramics on my F250 work truck for about 20K miles now. I got them for the reasons you stated, heavy loads going down long hills. I run just at GVW max and went thru the stockers in 25K miles. I really could not feel any difference from the stock pads when they were cold but this is a 2005 with ABS and discs all around. It shure helped with fades with long braking periods.

1997 T-100 4X4 Xcab,Warn Hubs
02 Camry LE
2008 Yaris