i cut warm season grasses here and we cut short at 2" height. i've cut some yards over 1ft tall before and yeah it will leave a few clippings but that's what they get for waiting so long to have it cut. they never seem to mind and they understand that it will not look perfect after being cut the first time.
on regular yards if cut weekly the grass is 4" tall and i cut it down to 2". on bi weekly it is 6" tall cut down to 2" and i side discharge and it never leaves clippings sitting on top of the lawn. if you run into a thick area during the spring you just mow over that one spot another swipe and the clippings are gone. i never double cut a lawn ever. even in the fall when mowing leaves i don't go over the whole yard 2 times. i just mow it all to the center and go over that one spot a few more times to mulch them all up and they disappear completely.
there is a difference between leaving a few clippings on a lawn and leaving huge clumps on a lawn. the clippings will disappear in about 4-8hrs after you leave. clumps will stay on the lawn and still be there when you come back for the next cut. i don't really have much of a problem with clumps but then again i don't mow in the rain or anything like that.
you can look at the pictures in my gallery and see there are no clumps or clippings on the yards after i cut. they look fine without bagging.