Thanks for the advice Dekay. I tried lifting the speakers, and having someone do that while I listened as well, and I couldn't hear much difference in relation to being lifted off of a solid base. I am not sure if that has to do with the mass of the speakers I am using...the Katans are 6 kg, and they are really small.
I will outline my experience here in case someone is going up against the same thing:
I too have a rectangle room, where I pretty much have to have the speakers on one of the short walls. So, that kind of limited me to positioning, as I was trying to keep out of essentially 2 corners. It ends up that the most likely listening position is further away than then distance between the speakers (2.4 meters for the speakers, 3.5 for the listening position). The nice thing with the Linn brackets is that they are adjustable both verticaly and horizontaly. They also seem to be a very solid design, nice and heavy, screwing into the back of the speaker. I would suggest them to anyone thinking of mounting a set of speakers that are up to about 8 kg or so.
About the wall they were going on, it is drywall, 1/2 inch, with about 8 cm or so before there is a sealed insulation cavity. Beyond that, there is a solid wood wall ( 2*4s stacked vertically: 1930s construction in Norway). One one speaker, half of the bracket caught a stud, and the other half, along with all four mounting points of the second speaker, I used a wood anchor (plywood, a little larger than the bracket, slipped behind the drywall via the temporary hole we made for running the speaker cable). I didn't use normal drywall anchors because I was nervous about them ripping out of the wall, and I wanted to add at least a little bit of mass behind the bracket.
Result: Very good! I was worried about the wall, thinking it would do strange things with the sound, but it really seems like it is not much of a factor except I did notice the bass being a touch muddy...I backed off the bass on my Classik, and that seemed to make a very subtle, good difference. I will experiment with this, as well as the angle of the speakers, to try and improve on things.