I am looking to purchase an inexpensive mandoline or a v-slicer. I want it mainly for thinly slicing potatoes (like for au-gratin dishes). I was going to get the Progressive Mandoline or V-slicer that Cook's Illustrated recommends, but it doesn't get great reviews on Amazon. So now I'm looking at either the Swissmar Borner or a Benriner (it seems like the Benriner gets mentioned quite a bit on this site). Does anyone have any input on either of these?