Can't afford Fab Filter's Saturn? No problem, get XCTR. It may not be as versatile, nor have the same saturation models, but as for multiband saturation it gets you fast where you want to go with your mix.
Put it on your mixbus or instrument busses to enhance the sum. Use it as an exciter in the master bus. Use it to shape a complex vocal.
Only gripe is it crashes your DAW whenever you press the presets button. But who needs presets with a plugin such as this?