I drive a big rig w/10spd at work everyday and when I go home, I just want to put it in D and relax. I have a D/A w/drw now, but just ordered a new 600, 3500 srw. I carry a 10`caribou and pull 4200# jet boat or pull 3 atv`s on a trailer about 15 times a year. Hope the 48re holds up. Sure will miss the allison. Wish the 600 was sitting in my garage right now. Hunter