These plates are great. I have a set in the shop. I usually keep the fine or extra fine right on the bench when I am using my chisels to keep them sharp while working. Once an edge is created it is just a matter of a few swipes to maintain it when you start to feel resistance.
The video a pretty good demonstration of how quick they are.
Also, to clean them all you need is comet and a scrub brush under warm water and they are good as new!