I have never run a machine at 6 , very rarely at even 5. If you have the right technique, let the machine do the work and you’ll get the correction done. Without trying to sound like a butt, please look at the posts I’ve made or look at our Instagram page for some before and after. All done with various da machines at about 4 for speed.
Guess it`s a YMMV situation, or a matter of differing perceptions regarding how long to spend on such stuff.
So I`d be a bit circumspect about saying "if you have the right technique" as I seen nothing *wrong* with using the higher speeds a the technique that has served me fine for so long. Heh heh, what..I should quit doing something that`s been 100% satisfactory for decades or stop recommending the same to others?!? I`d sure never expect *you* to change what *you`re* doing or recommending since it works so well for you. We offer two differing opinions and people can decide which, if either, way to go.
Not questioning your expertise or your work at *ALL* Mike, I think it turns out great and you`ve helped convince me to try stuff that I might not have othewise. No question that at a lower speed you can get the same results in a safer (for the paint, the pads) manner and if somebody prefers that route, great! And even if it`s a case of erring on the side of caution, that`s better than going the other way!
I just don`t see any reason to say/imply that doing it differently is wrong or that being more aggressive is (always) too risky. I get faster results with zero downside by running my polishers at their tops speeds much of the time, and none of mine came with caveats against using that top speed, if fact it`s often touted as a feature.
Hey, I seldom run my polishers at top speed on the `93 Audi, much less the Jag, because they`re just too fragile. But those are very unusual situations. Knowing when to be more/less aggressive is one of the basics and I assume people give that proper consideration.