I just picked this up after well ... forever.  I had been entering 0, thinking I was saying no swing when quantizing.  I should have been using 50.  As Homer would say Dohhhh.  Just an FYI.
 
Swing. Use this value to make groups of even eighth notes (or whatever note you want to enter
in the Resolution field) “swing,” instead of playing with exact eighth note rhythm. A value of 50
percent, or “50-50,” produces equal durations for both notes—no swing. A larger value makes the
first note longer, and vice versa. See “Swing” on page 768.

That is a very helpful hint. Thanks.

I use the same function in Notion 6. I used to use the midi effect in Sonar, but found it harder to get right. One of the things I've found useful is to have very small variations on each instrument. Elton John called this playing between the notes. To achieve this, think about the famous Beatle back beat. Ringo is almost always just behind the beat, think his washy cymbal playing and Macca's is just in front of the beat...its how u create push and pull within a track. To achieve this...you would push the swing feel of the drums back by a notch or two and the bass forward a notch or two...once you get really good at the technique, you can match the feel of say an acoustic guitar that is acting as the anchor of a whole track. Even I can't play 100 percent metronomically all the time :). And then there is feel too.

Ben

Also 66% is a perfect swing (Like quater note - eigth note in 6/8), past 66% is over-swung which is great for EDM and Jazz swing. under 50 is under-swung (or negative swing). Very useful feature in Sonar. Cubase for example won't over-swing or underswing unless you use groove quantize and have already imported a swung or under swung midi clip into the quantizer.

Ken - somehow I had overlooked this setting completely in the regular Quantize dialog for years! I have always been using either Groove Quantize or the Step Sequencer for getting swing. THANKS! :D
 
It's also nice and convenient that it's possible to re-apply swing with different settings (even lower levels), without having to undo in between.

I have a little workflow pattern of plugging in a pattern int the step sequencer, but using the Quantize Midi FX  to add a touch a swing that suits the bpm. Then applyng the FX and dragging the beat to AD2, in there use the Transform tool the massage the dynamics. Take the result of this and drag back to the midi track. Convert this to step sequencer. Now the swing Step sequencer is showing as timing offsets (or I let the step sequencer be quantized again with no timing off sets and I apply the Midi Fx to it again. 
 
Seems as a genera rule, the slower the BPM the more swing you can apply, and percussion has stricter swing than harmony parts.