I bought this sharpener because of the low price and small size, and it fits the bill perfectly for this - However. Because of its small size its a bit difficult to use if you have big hands, and with small blades you cannot get enough stroke on the pull through and the blade consequently gets a bit pulled to one side. On larger blades this problem is overcome.
I also must say that using the ceramic or fine side actually blunted what was a previously sharp blade, so had to go back to using an oil stone to get the sharpness back.
In fairness though it does bring longer bladed knives with a dull edge back to somewhere "near" sharp, so could be useful on longer trips.
I would not however recommend this as your only sharpener, and I would have given a lower rating if it hadn't been for the low price.