My experience with Xanax was good - for only two years or so. Personally, I build up a tolerance to anti-anxiety and antidepressant medications. I don't recall the dose I was on, but it did help. After I built up the tolerance, I was switched to Ativan, which NOW no longer works effectively, and I'm stuck with anxiety and panic frequently.
My experience with Ativan was a little better than with Xanax. Ativan was very helpful in the beginning, it 100% helped my panic and GAD. Then, over the course of two years, 1mg would only help for a hour or so.
Xanax, I thought, was helpful, but milder than Ativan.
As of 2 weeks ago, my new psychiatrist has me on an old-time med - Librium. It was wise to make the switch, because even the smallest of dosages of Librium control the anxiety.