I've used a Lansky enough to have a collection of worn out and broken stones. For doing a couple of middle sized knives it is not too bad. For a huge collection.... not so much.
If you are going to get a lansky, My recommendation is to get the starter pack, and then get the course and middle diamond stones. The course and extra course natural stones are pretty well useless on anything but pretty soft steel. However, the lansky system is expensive, the diamond stones don't last all that long, and the other naturals do dish pretty quickly.
The entire system is based on getting the same set-up every time, so it takes some work to get the rods straight, get the clamp on the same every time. It does work. I've gotten some really good edges with it. and for someone who doesn't have great motor control, or just wants to look after a couple knives, its very good for that. I gave all my stuff to a friend who has also had good luck getting some edges started on knives.
But its not magic, and if you have the patients to learn free-hand, that will be much better long term.