It's a one time deal on the valves, whether that is the blower, or one of their trimmers.
Husky owns Red Max, but Red Max makes the blowers for Husky to Husky's specs, which is why the straps and air box covers are different. The 570 is the same as the RM 7500, and the 580 is the same as the RM 8500.
The 580 is even more powerful, but it is a couple pounds heavier, and believe me, you can feel it. I am betting after a couple hours of wearing it, the difference would be even more pronounced. The reason I went with the 570 is it has excellent CFM's 770 vs 912 for the 580, but it had 236 MPH vs 206 for the 580. The higher MPH helps with scouring stuck down debris, yet it has more than enough CFM's to move any pile of leaves. Believe me, I gave it a good workout last fall on some huge piles.