You can achieve excellent results with a PC too.
The dusting that you are experiencing is proabably the product drying out a little, you are possibly working it too long, or you have the PC running too fast, or it is very hot where you are.
It does take a little experience to remove swirls, and you do need to be using the correct courseness of pad and working the product until it is transparent, then wipe off and check, if the swirls are still there then do that area again.
You will probably need to apply some pressure to the PC, I would suggest setting it at 4.5 and pressing down until you feel the motor lag, then just release the pressure a little and then treat the area, then you may have some success. Go slow and repeat the process if necessary, you should probably move the PC across the area with the suggested pressure at approx 1" per second or so. Use overlapping movements, and as suggested above you can spray your pad with a little water, don't use too much and don't mist all the time, just occasionally. I hope this helps.