For me, Ativan did nothing more than make me so sleepy that I couldn't function. I don't remember the exact dosages, but on a low dose, it did nothing for me, and on the next dose up, I was barely functioning...I kept just falling asleep.

For me, Xanax works great! Sometimes, when my anxiety is really high, I need a slightly higher dose to combat that overall muscle tenseness. I've found that on a normal day, the effects last about 8 hours and on a high anxiety day, it lasts about 4-6 hours.

I think I basically had exactly the opposite experience to what you've had. Ativan did nothing to relive the internal tenseness that I always feel...just made me sleepy. Xanax does relieve that tenseness and doesn't make me feel sleepy at all. I did have to play with the dose and timing of the Xanax to figure out what will give me the best effect, though.