Thanks for the replies. What exactly is a dual action? What makes it safer?
I like the price of the silverline but a DAS6 is only a bit more and if it's safer I think I'd rather go for that.
A rotary spins on a central axis while a DA oscillates at the same time as it rotates.
If you held a rotary in one place on your car, eventually the friction would cut through the paint and down to the bare metal. Because the head of the DA is always moving, even if you held the machine in one place, the friction would be spread over a larger area reducing the risk of 'strike through' as it's known in the trade. Couple that with the fact that a rotary can spin at much higher speed than a DA and the potential risk of strike through is further increased.
However, there are some high returns for the added risk of using a rotary. First of all it's faster, secondly it (arguably) can achieve a better finish and finally the oscillating motion of the DA can be more uncomfortable and harder to control (when I say harder, it just requires a different method to move it around the bodywork).
Now I was in your position back in February. I knew nothing about machine polishing and the 'risk' of a rotary scared me to death. However, I did a lot of research on the theory and methods of using one. I looked into which machines, pads and polishes would be most suited to the kind of paint I would be working with and I came to the conclusion that I would give it a go.
I got all the gear for my birthday in March (that kit from I4D) and then used my girlfriend's Corsa as a trial run before letting loose on the E60.
If you go back a bit in this thread you will find both of my posts where I worked on the Corsa and did a bit of correction on the E60.
If I, as a complete novice, can handle a rotary I don't think anyone should be scared of them. It just takes some time, research, patience and practice to reduce the risk. Trust me, the reward is well worth it.
