I've taken Xanax XR. I still had panic attacks and anxiety while taking it. I take 125 mg of Zoloft right now and the Xanax XR if needed. The Xanax XR is a once a day dosage meant to do exactly what it is, tranquilize--versus taking regular Xanax when you feel an attack. My psychiatrist felt it was too addictive and wasn't helping the problem, only medicating it. The Zoloft is getting to the root of my anxiety and if I do feel a panic attack coming on, I can take the Xanax XR. I have not had a panic attack while on the Zoloft and have not needed the Xanax XR (extended relief). Although, early on when I began Zoloft, my anxiety was heightened which is a normal side effect. It also increases my anxiety when I increase my mg of Zoloft. This is all only temporary as when my body adjusts to the new level, I level off as well.
Hope this insight helps!
Bonnie