Like scott123 said - I would rather spend my money on a mandolin of excetional quality - using the shield that comes with it - than using a "V" slicer - I'm guessing but is it made of plastic? I have had both and I found that the plastic bends, thereby causing you to press even more firmly. The stainless mandolin doesn't give at all and has several blades and a very controlled thinness or thickness - the "V" slicer I had had set blade heights of which I had no control.
The big difference - other than the materials used - is also in the safety guide. Check out the Bron versus the "V" guides Bron
- V Slicer
The Bron closes down ON the food you are slicing and has a "frame" around the food and your fingers not exposed to the blade at all, the V slicer requires you to actually press down on the food while holding the guide - hoping it doesn't slip, and you know the rest...