How clean do you want your brass, and how much trouble do you want to go to to clean it?

A vibratory tumbler is easy and simple to use, and it will take all the superficial crud off of and out of brass, but it won't clean the primer pockets, and it won't touch tarnish. Plus that media has a habit of sticking in the flash hole and you have to deal with that.

A rotary tumbler with pins and detergents of your choice takes more steps and work, but it will make even the dirtiest, cruddiest, most tarnished brass look new... period.