I've got one; or rather, my wife's got one, and it's very efficient and fast. However, sometimes I want my vegetables julienned, or my onions cut into half moons, or in big chunks. If I'm making an onion/cashew nut base for an Indian chicken dish, for example, I just chop the onions into chunks - and the gadget you show doesn't do that for me.Does anyone have any objection to such tools? Here's one (refer to photo) my mum uses for onions and it's crazy fast.
to answer your question again - no objection at all. Whatever makes it easier for your cooking. What do you like to cook?