With a rotory buffer it is good to have trigger pressure it makes the buffer a little more versatile. The Dewalt (DW849) is my favorite rotory buffer it runs at 1,000rpm - 3,000rpm. Running this tool between 1,000 - 1,500rpm is usually all that is needed. Use the trigger to fine tune your technique. The difference between the PC and a rotory buffer is the PC oscilates (OPM) and a rotory buffer only rotates (RPM). Even though the 2,500 - 6,000opm seems high it does not generate near as much friction as a rotory buffer does at 1,000rpm. Practice with them both and always stay relaxed.