Clipper plugs generally have a softer knee to the clipping, which somewhat reduces the high freq crap.
Some (eg T-Racks, GClip, & others...) let you determine how soft the knee is.
The resampling on GClip will make it cleaner because the plug is not just chopping the tops off (as overloading your DAW master would), it's actually reshaping the higher-level portions of the waveform, so resampling allows it to average a more "accurate" final output. GClip actually graphically displays the transfer curve.
Also the behaviour of the plug on the flattened tops of the waves differs from plug to plug - eg SweetBoy's Volcano leaves the tops flat, Voxengo's Elephant seems to drop every other sample a notch for the duration of clipping, so the output will not be DC...some step down each sample one notch.
You can see the effect by zooming in vertically with WaveLab.
BTW, I don't think having the plug avoid DC on the peaks is important if you plan to dither the final track as that would break up the DC anyway...