The thread "Forget the Dust Deputy" was so slanted against the Dust Deputy that there was no discussion.
Have you spent time at the Thein Baffle website?
Anyway, I have done way too much research but have not experienced either system, although I will end up with a dust deputy. My sense of it after my obsessive research binge is that if you have the time, would enjoy the build, and want to save a little money, especially if you have scrap sheet goods you can use, is that you will be very happy building a separator.
If you have a backlog of projects and don't mind spending the cash, buy a Dust Deputy. You will be very happy with it.
I believe that this is also the opinion of Paul Thein, who invented the thing.