first to the OP.are you wanting to know about tumbling or vibrating.they are both two different things.
one vibrates to work and the other tumbles.one uses a media to clean along with some sort of agent or not( corn cob/walnut )the other works with a harded type of media say SS pins and soap/water.you have to dry your cases all so when you tumble.( not my thing )
the vibrating kind for the most part is the cheapest way out.the tumbling can get rather high.but most have changed or want to.
heres my thing.I like to use the vibrating type with a cheap car polish with corn cob media.I don't think the inside of the brass really needs to be as clean as the out.as long as the out side is clean I know I want hurt my dies.( and it looks good)I even use old dryer sheets to help with the dust.my media has been used for some time now and still going.
to me you can look at it this way.just how clean do you want your brass to be.then you will come up with the money to buy what you think will do the right job for you.its a mind thing to me more than anything else.