I use a G4 Cube as my main OS X machine and it too has a PSU brick. But in the case of my Cube, I have the space to hide the brick. But on the little table where I have my compact Mac, I have no nice place to hid such a brick.
So it all depends on your situation. Even so, the Mini and Cube were made to use a brick, the compact Macs were not (something that matters to the purists among us, myself included).