I'm on Wellbutrin XL for Panic Disorder. I first started to kick in about a week and half in. The only thing I didn't like about it was for a month straight everyday I'd get the worst stomach cramps, nausea, diarrhea and weird sleep patterns. After that month the drug worked great. The con is you really can't miss a dose, you could possibly miss a day, but you miss anymore and you get pretty bad withdrawal which I never want again. The biggest pro I got from this drug was I quit smoking after 15 years.
If anything ask your doctor what you want. I was prescribed Wellbutrin to help with my PD and my smoking. I'm sure I would of been given something different if the smoking wasn't a factor