My experience has been:

1) it helps to oscillate in the queues where there are batch jobs
(otherwise, the most recently introduced batch job gets the CPU at the
expense of earlier jobs that are nearing completion); and

2) it helps to decay in the queue where interactive users are working
(otherwise, somebody doing a CPU intensive task that really, really should
be done in batch will adversely affect other interactive users).

We go a step farther and overlap the C and D queues (so the person doing
that CPU intensive task in the CQ will soon learn that they could get
better throughput by putting their task in the DQ where it belongs).

For example:

                    ------QUANTUM-------
QUEUE  BASE  LIMIT  MIN    MAX    ACTUAL  BOOST  TIMESLICE
-----  ----  -----  ---    ---    ------  -----  ---------
 CQ    152    232   25     100    25      DECAY    200
 DQ    200    234   100    100    100     OSC      200
 EQ    236    253   2000   2000   2000    OSC      200