A friend of mine bought this, hated it as it ground her blades down, and asked if I wanted to try it.
Thankfully I only used a £10 cheapy knife to try it because of her warning, as if I had used it on one of my £100+ knives and watched all of those metal shavings come off I'd have been furious. All sharpeners obviously take some of the blade off, but this should be a minimal amount and certainly not shavings as this did - there were actual tiny curls of metal in them.
Admittedly the knife (well, most of it, as the tip didn't want to know) was sharp after going through this, but that's a moot point really as if I used it a few more times I reckon I'd have ended up with something resembling a scalpel more than a paring knife.
This is now in the bin where it belongs and I'm carrying on with my whetstone - laborious maybe, but at least my knives won't disappear after a few uses.