Before I upgraded to the Microsoft Natural Ergonomic Keyboard 4000 Black, I was using an earlier model of this keyboard for a number of years. In contrast to the earlier version, the keys may now be depressed gently and quietly, the spacebar can now be depressed evenly, and the keyboard will no longer squeak when it is moved about the table. I have no reason not to suggest it to anyone because there is nothing negative to say about it. As someone who has used keyboards of this sort for a very long time and has a lot of experience with them, I am extremely pleased.