... same dose per day or are the meds different (besides absorption time).

To be clearer, I guess I'm wondering if it breaks down to release the same amount of medication per hour whether it be XR or IR.

I have also read that the Xanax XR only lasts for about 12 to 15 hours. If that's true, then should I take 1x XR twice a day instead of 2x XR once a day?