I think the consensus is that the Oneway is easier to use, but the McNaughton is more versatile, but with a steeper learning curve. The Woodcut seems to be the most limited and least robust of the three.
I have the McNaughton, and haven't used it as much as I would like. (I started running low on large green blanks about the time I got it. Most of what I've got in the pile now it pretty dry, and more difficult to core.) I'm not quite as fearful when I use it as I used to be, but it's still got a fair amount of pucker factor involved when I use it. I've had more belt-screeching stalls with the McNaughton than with any other tool. (In fact, I think the McNaughton is the only thing I've ever stalled my 3520B with.) Someday I would like to add the Oneway system to my arsenal, but it's a pretty low priority on my tool wishlist right now.