I have use gesso. I used it as a base on paper so the next media didn't sink in. I used it in an altered book, to cover up or soften the printing in the book, so I could paint or stencil over it.
But I have also used it to stamp with! So much fun! You brush or spong the gesso on stamp, then stamp. Let dry. Then stamp over it. The first item you stamped with the guesso now looks like it is farther back, from you. Really cool look!
And I used both brands you wrote. One was thinner, but both worked the same way for what I was doing.
But I am not an artist, just a craftperson. Maybe that is the difference. My oldest daughter is an artist an is much more picky about products she uses.