If you need the "stage presence" to sell your band's image and are young enough to schlep it around, go for a head/cab.
If you're not trying to "sell an image", don't drive a van or don't want to deal with a lot of weight, go with a combo (although tube combos aren't light either).
Sounds like you are assuming that Head/Cab means giant marshall head and 4x12 cab. I prefer smaller amps, and smaller amps generally have more issues with rattle because of the lower mass and proximity to the speaker. A small head and small cab is the better choice IMO. It won't break your back, take up much space, and has nothing to do with image.