Personally, I haven't noticed anything from ativan in the first place, but pretending its equivalent to a benzo that I have noticed its effects, unless you are trying to take a really amazing nap you will be sorely disappointed. I am prescribed klonopin 2mg 2x a day one being before bed to be taken with 100mg of trazadone. Nothing harmful can come of the combo but its not something i would personally enjoy trying to get some sort of high out of. If you have effects from the ativan(noting it is a sedative) alone then adding a sleeping med on top seems pointless (again in my opinion). Traz is a non addictive non narcotic sleep aid.
Hope that was helpful.