SFX 1,2,3 are fantastic polishes. Like the doc says, SFX 3 I think is one of the best finishers out there. You get a lot of Zaino freaks on here and there is a reason for it. Zaino makes great stuff. But I tend to stick with the Sonus polishes because I deal manily with soft Euro BLACK!!!!!! paint. I detail Bentley's, Ast. Martins and Rolls the most and would be lost without the SFX line of polishes and pads. The Yellow (sfx 1) pad is one of the most versatile pads on the market. The White (sfx 2) pad does a great job of bringing back the luster and depth. The sfx 3 pad I actually have two different colors with. The blue and red. For some reason the red is a lot softer and gets used the most.
Now, if you are dealing with harder clear coats you might need a pad with a little more hmph then the yellow pad. But I believe the SFX 1 polish is right up there in cutting power with some of it's comparable comp. Even though it is pretty easy to find stronger polishes.
So if you ask me, I think you will really enjoy them. I do believe they were made especially for DA line of polishers. I use something different with my rotary, but if you are using only a DA polisher then I think they are the best.