Both Microsoft Natural Ergonomic Keyboard 4000 and Comfort Curve Keyboard 2000 are simple low-mid budget products. Each of them incorporates some new feature to enhance the users productivity, but nothing major has changed (except Natural Ergonomic Keyboard 4000 gull wing design). These are good, solid and reliable products which can find their place on one’s desk or under the Christmas tree as fine presents. Natural Ergonomic Keyboard 4000 is product designed for the secretaries (or anyone who works heavily with the documents), while its little brother, the Comfort Curve Keyboard 2000 can really be used by anyone.