I recently took the plunge and bought a Lansky system. It's like a dream come true on my pocketknives - in less than 10 minutes I can get one literally sharp enough to shave the hair off my knuckle. My kitchen knives, on the other hand, are made of a much tougher steel and the Lansky stones take a VERY long time to even make an appreciable change in the blade's sharpness, let along put what I would call a good edge on one.
It shouldn't most kitchen knives are high carbon steel and, therefore softer than most pocket knives. Are you using the 20 degree on the Lansky?
Reading this thread, I have just - courtesy of Mr Google - been looking up the Lansky, - which I had never heard of prior to today - cited in posts made by @Tomorrow and @lowendlinux; is it as good as all that, or, is it worth purchasing?