I tried the little xxx's down the wall in a two foot width, and when dry that's what they looked like.
I started with a thick undercoat, I filled the roller with paint and used slow very very light delicate pressure ( my rollers are still good and very usable) taking a little off the edges of the roller to avoid the noticible lines down the wall, and also did the sweep from ceiling to floor. It actually made a very nice finish, not at all too motley. Velvety looking it was. When washing the rollers, don't scrub them, just hold them under a faucet and gently use your fingers to get the paint off.
My success came from reversing the xxx's and doing it on an upsweep instead of a downsweep, starting at the ceiling. Also I followed your advice about random xxx's but I did not go all across the wall. Instead, I did it in about 4 foot sections going down, also in random spots. I would start in the middle of a section and work up down and across so that it kept connecting with all the other xxx's, again very random and much bigger xxx's. probably 10 inches instead of the little 6 inch ones. At this point, I did not put too much paint on the brush just enough so it went on nicely but not thickly.
I find with this paint you really have to experiment with it on the wall, and get your pressure, speed and technique sorted out. Without a teacher it's pretty much trial and error.
The result is a suede wall. We are very happy with it. I'd use it again. I used 31/2 cans of paint, because I did one wall twice and had a spill...oops!