It seems that they made groove quantizing more convoluted in SX after v5, but here's how I do it.
For simple positional quantizing, use
MIDI > QUANTIZE SETUP. Here you can choose how much gets quantized, how much gets left and whether it just moves your part closer to the quantize points or right on it (bottom right of window.
(apologies for the size of these - I have no graphics software on this computer to resize)
If you want to use velocity and/or note lengths in your quantizing, you need to set up a groove first. Go to an editor (I find the drum editor works best, but then you don't get to use note lengths) and make your groove - move notes off their quantize points, set velocities etc....
Then go back to the main window, select your bar of groove and choose
MIDI > ADVANCED QUANTIZE > PART TO GROOVE.
Now if you go to quantize set up, you have some additional options to set up your groove...
Once again, you can choose how much gets quantized, how much gets left, and how tight that quantizing is. The key here is the random quantize which will move notes off their quantize point to give that human feel.
If you use this feature, once you've programmed a couple of different drum patterns for your song, you can apply it throughout, add some of this randomization, and then go in and add fills and make other changes. I'm not suggesting that it isn't significant work to create drum parts, but you certainly don't have to play them manually, one bar at a time.
Rich