I'm not sure I know exactly the kind of sanding brushes you are talking about. Can you give us a brand or model or other reference or link to an online ad? There's no restriction on use of brand names here.
Flex trim is the brand.
The flat disc with the brushes going almost to the center is the one.
A sales person from the company said it would work th sand the profile on raised panels,
so I also would like feedback from an actual user! www.flex-trim.com
My company manufactures a Jenkins' Shape & Sand machine that features two counter-rotating quick-change cope spindles and two counter-rotating quick-change sander heads. We have built many of these machines, and the Flex-Trim sanding heads have been our customer's choice almost exclusively. They provide a finish that is in my customers' opinions at least as good as other rigid heads without having to change the sanding head for different panel or outside edge profiles. They will usually set you up with a consignment head where you would only buy the brush strips, and only pay for the head if you keep it. From all of my experience with these heads, I wouldn't recommend any other for our applications.