I bought one of these thinking that I would use it constantly, but I always find that the egg gets sort of smushed when I use this. It doesn't slice it up all nice and neat like I thought I would, I kind of have to work at it a little to get it to go through. I ended up just tossing it into the back of a drawer somewhere, and a paring knife works much nicer to get straight neat little slices that don't crumble apart as I cut through them.
This product is one of those additions to my kitchen gadget collection that I actually use. Whenever I make egg salads, I just stick a hard-boiled egg in there and it slices it up. My son loves to do it and it makes him eat more egg, which is good for him. Sure, you can use a knife or a masher to do the same thing, but this is so much faster and way more fun!