I have never tried Ativan.
I can only tell u from personal experience, at the beginning, a 10 mg diazepam was somewhat equivalent to a 1 mg alprazolam.

I say somewhat, because diazepam had more muscle relaxing qualities as opposed to the alprazolam.

However, after being on 1 mg alprazolam daily, for over a year now ( for anxiety), the 10 mg diazepam has absolutely no effect for me.
I am sure it's a tolerance issue. The small dose of alprazolam I take daily , however, continues to work very well for me. ( Knock on wood )

Hope this helps, sorry can't help u with ativan .