I got a set of these, and they work fine. They can be a bit of a pain at first, but the rachet and straps have been the best thing I got to do the job. Dink never moves.
When I bought my Davit's from Kato, I also bought two sets of stainless ratchets for $65/each. They do not rust but unfortunately they do not work very well either... the ratchets are a piece of shxxxte.
That is one purchase I regret.
So, the other day I went to wally mart and picked up a good ratchet (non stainless) for $15. Even if they rust in 2 years, I can buy 4 units for the price of one stainless from kato.