Sort of curious as to when some of these power filters came out.
From my reading, I understand the Metaframe Dynaflow came out in the mid-6o's. If it is not the first, it's among the first. I got it much later, '74-75, a Birthday present from my oldest brother. I had both going on my 60 gal. for a while (the Dynaflow and the Hagen Bio-zonics) and seems to me the Hagen was a slightly bigger pump. Also had the smaller sized Hagen, that I never really had it working very much. Wiggle and wack is how you had to start these magnetic drives after a few years of use
I was around aquariums from a young age, and got my start in the hobby when I was given a 60 gal. (52" x 16" x 16") in '73-'74. I had 2 brothers much older then me who would have purchased the Hagen power filters, probably somewhere around '70-72. These pumps were already sort of worn out by the time they were handed down to me.
One of the things I got with the tank was a fairly extensive library of fish books. One of the books, called Oscars (I believe it came out around '69-70) talks about power filters and shows a picture of a Supreme power filter (If I recall correctly) so the Supremes were also already around in the '60s. Two J-siphons (If i recall correctly) so probably an Aquaking? Unfortunately I accidentally got rid of all these books sometimes in the '90s by using garbage bags to move and mistaking it for garbage
I think the Supremes came out first...and the Aquologies were the imitation or knock off. This link shows an Aquology 600 in great detail. 1976 copyright, so probably the date that first came out (?).https://picclick.ca/Vintage-Aqualogy-Power-Plus-600-Aquarium-Filter-323166178360.html
I know in the late '70's, Aquology had a lot of advertising in the magazines; Supreme not so much. One advertisement I do remember is an Aquology 1200. Two pumps and 8 j-siphons all in one double length box. Of course what is the point of that, it's just like 2 except it would be one cumbersome box. Yeah, It's about gph and bragging rights for the biggest pump.
I did find pictures of packaging for the Supreme Superking that shows they came with 4 j-siphons or 2 double J-siphons. Second row on this link shows one box with the 4 j-siphons and a couple others showing the 2 double siphons. https://www.google.ca/search?rlz=1C1SFXN_enCA498CA498&biw=1600&bih=769&tbm=isch&sa=1&ei=OLjlWu6dNouN0gKnnJvgAw&q=supreme+superking+aquarium+filter&oq=supreme+superking+aquarium+filter&gs_l=psy-ab.12...170852.170852.0.173422.214.171.124.0.0.0.184.184.0j1.1.0....0...1c.1.64.psy-ab..0.0.0....0.sJzk7Q3gUfs
I think the double j-siphons came out much later, like mid to late '80's(??). I also did find pictures of packaging for the Supreme Aquaking that show 2 j-siphons and a single double siphon( though for some reason can't find the picture now that shows Aquaking packaging with 2 single J-siphons). This shows a Supreme Aquaking in great detail:https://www.monsterfishkeepers.com/forums/threads/brand-new-aquaking-power-filter.478664/
.They call the double j-siphon a "king siphon". This short youtube link shows what I think is a later model Supreme Superking (black with 2 double j-siphons), Aquology 300 and a Dynaflow. All pumps I owned in the past:https://www.youtube.com/watch?v=ayib7ah2Vf0
By the mid '80's the modern style of HOB was out in full force (particularly the Hagen Aquaclears). Sort of hard to compete with something you just add some water, plug it in and it self-primes. Way more convenient. So I would imagine the double J-siphon is sort of in response to this, as setting 1 or 2 siphons is at least less of a PITA then setting 2-4 or more. The change to black color, probably in response to their knock off competitor, Aqualogy, since they were black.
There is something to be admired for equipment that lasts. Possibly, also, part of the downfall of these direct drives. Once you purchase it, you may not have to replace it for 20+ years. So that as well, would hurt sales, as they don't have to be replaced very often. Can't say I have ever owned a piece of Aquarium equipment that lasted as long as the Supremes and Aqualogies. I am sure people have had Eheims that have lasted as long or longer, but they were always very "pricey". First seen those on the show tank at a pet shop in the late '70's. Certainly wanted them, but were way out of my price range.