1mg of Xanax is equal to roughly 15 or 20mg of Valium but doesn't last as long and feels different.For one thing,Xanax doesn't have the skeletal muscle relaxant properties of Valium and is just a different buzz.Xanax hits faster and harder and is more black-out inducing.Valium is more subtle and mellow.Some people actually prefer Valium for this reason.Personally,my favorite benzo effects come from a cocktail of the two,leaning decidedly heavier towards the instant release Xanax, with a few Valiums thrown in for their longer duration and more loose,sedating feeling.Valium has always made me sleepier than Xanax and for some reason dries my mouth out more than other benzo.As trainspotter mentioned,Xanax XR is time released so you have to take more to get a buzz if that's what you're after.If you suffer from panic attacks or severe anxiety Xanax is definitely more effective since Valium comes on slower and has a more "even" feel to it's come up.Both are good though and of the benzos I've had,Xanax is my favorite and most effective choice, with Valium running a close second if taken in high enough doses.If you like Xanax you'll like Valium too,you just have to eat more of them.