Oh Larry, Larry;
Yes yes, I see where your info is coming from. My old manual here has the exact same wording under "Remarks" for the powders.
Red Dot = More "100 Straights" have been shot with Red Dot than all other powders combined'
American Select = Our newest premium target powder, Ultra clean burning, Slow pressure rise for less shot deformation, tighter patterns, less felt recoil.
Green Dot = Produces tight, uniform patterns and soft felt recoil in 1 and 1 1/8 oz 12ga shotshell loads.
Unique = A versatile all-around powder for over 100 years, handgun to shotgun.
Herco = A proven powder since 1920 for the ultimate in 12ga, 1¼ oz upland game loads.
Blue Dot = The powder of choice for 1¼ to 2 oz Magnum shotshell Hunting loads.

So Larry answer your own Question, to what indeed, are they comparing the less/soft felt recoil of American Select & Green Dot. You say they did not make such statements about the slower powders, I say they "Also did Not " say it about the faster burning Red Dot or Bullseye.. Secondary use for Bullseye is listed as light 12ga target loads.
In this older manual which was in fact introducing the new American Select, as I pointed out they devoted two pages to showing exactly what the comparsion was to, "A Typical Fast Burning Target Powder" That Larry was "Red Dot".

I quote directly from this guide;
""Alliant Powder's ballistics research has demonstrated if it has a FAST burn rate and QUICK pressure rise, it can give you flattened and deformed pellets"" After some discussion of the effect on patterns this follows; ""There's another side benefit of American Select's burn rate, too-less felt recoil. It's more like a PUSH than a PUNCH, so at the end of a long day, you'll be ready for those late shoot-offs.

A "Push" is slow in comparsion to a "PUNCH" Larry. This is the ""EXACT OPPOSITE"" of Thomas' reasoning.
If you still can't understand that, then I have made a Terrible Mistake, I had credited you with having at least some intelligence.
At this point I am not even trying to determine whether Thomas or Alliant is right , but to simply get you to see they are opposite in their conclusions. Personally, you see, I think they are both wrong. I think "BOTH" IMI & Alliant were/are puttting out Propaganda for the purpose of an attempt to increase sales of a particular line of powder. It matters not they were already selling the powder they were supposed to be improving upon, this is done everyday in advertizing. Just look at all the products which are "Perfect" today & tomorrow they'll introduce the "New & Improved" version.
Remember the old Burma Shave roadside signs in which they so ran down a mug/soap/brush method of shaving. Do an E-Bay search on Burma Shave & see just how many Mug/Soap/Brush combos come up bearing a Burma Shave logo. Wonder where they all came from, surely Burma Shave would not have bad-mouthed a combo they were in fact selling ""WOULD THEY"".
There is an old saying that about 98% of advertizing is not to help you solve a problem, but to convince you that you actually have a problem.Once convinced you have the problem then you will likely look to the one who convinced you for the solution. Most people would have never felt they had a problem with recoil while shooting mild target loads from a heavy gun had they never been so inundated with "Snake Oil" cures for it.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra