From my experience it depends on what you are after. Clonazapan offers a very reliable calming/things are going to be OK feeling for me. But it also makes me sleepy and lathargic, and it lasts like 12 hours. I cannot take it if I actually have to function. Ativan on the other hand is not as reliable in the warm fuzzies I can get through it feeling, but it only lasts an hour or so and even when it's working I can still do dishes and drive.
Like weedoge said though, my preference is the benzo with the narcotic. Personally I like 3mg of Ativan with 20mg of oxycodone. With that combo nothing in the world bothers me.
But because of the "epidemic ", I can't get my oxycodone anymore and it sucks hot sweaty balls. OK sorry. Rant over.
Mattie