The knives is my house never seem to stay sharp. The Ninja knives allowed my to throw away all of my dull knives. These are the best knives I've ever had. They are heavy enough that they'll stay in your hand, but not too heavy where your hand gets tired after using it for awhile. The top of the blade is much thicker than the thin sharp bottom of the blade. They are balanced really well. We use knives everyday in our house. Having the sharpener right next to the knives was an extremely smart move. As usual, Ninja has come up with another product that works amazingly well in the kitchen. These will probably be the last knives you'll need in your kitchen.