The Lansky system, like all similar sharpening gadgets, has a lot of limitations. It will work fine on some blade sizes and shapes, but it is a pain in the butt to use with others.
The angle guides are great as long as the manufacturer of the knife you're trying to sharpen happened to grind the edge bevel at that exact same angle. Otherwise you'll need to work a lot to reprofile the edge to fit the sharpener.
Recurves, hawkbills, convex ground blades, large blades (over 6") or very small ones are challenging to sharpen on the Lansky.
IMHO, there's no substitute to freehand sharpening. Learn that skill and a simple set of stones is all you'll need no matter what you need to sharpen. Start practicing with cheap knives until you get the hang of it, after a while you'll be able to do it by "feel" and you'll be free from those complicated and bulky sharpening jigs.
Now hatred is by far the longest pleasure;
Men love in haste, but they detest at leisure.
- Lord Byron (George Gordon Noel Byron), Don Juan
(canto XII, st. 6)