i read these are all made by the same manufacturer
are the only differences between each type of low end model the branding and stock fan(s) it comes with?
or is this actually a different/revised design?
Doesn't appear to be a rebranded Asetek. Only the Zalman CNPS20LQ appears on the Asetek site under OEM Customers - Do It Yourself. As to whether it's a different/revised design, I do not know.