Maybe it's because I'm tall, but I've never used the ladder on the back of my truck to climb onto the roof. I use the ladder (factory LR) as a handhold when stepping up onto the bumper. From there I can reach pretty much the whole back half of the roof. If I need to reach something further forward I can stand on the top of the tire or the sill. The tailgate of a RRC is even better to stand on. You can practically hold a concert on that thing.
I have to admit, it was enjoyable to sit on the roof rack on knewsom's Disco in Ensanada before the Baja 1000 a couple years back. Great vantage point to watch the world go by. Here's the man himself: