color space profiles are handy if you want to nail down your color calibration.
use it if you are into having the color space of the monitor match the output of your printer.
keep in mind though that calibration is the key word. if you get really serious about color cal you will accept the limitations of the system... or jump out a 10 story window. current hardware drifts a lot in its color output. again, if you are hardcore, you will get your own calibration tools - get custom profiles for your printer and a calibration eye for your monitor.
a big part of the problem is that monitors are light-emissive devices and printers are light reflective output.
fyi: most calibration ICM profiles are not very good, and windows can only use one profile for one video output device, e.g. 2 different monitors one one card will use the same profile.