Microsoft has refined its previous Optical Desktop slightly to come up with this Bluetooth version. The chief difference is that it trades in the large RF receiver for a compact Bluetooth dongle. The mouse is slightly heavier than before, perhaps to accommodate the Bluetooth technology. Because of that and a different curvature around the thumb groove, it's a bit harder to pick up and reposition than before. The keyboard is extremely well laid out, with large media keys along the top and a scroll wheel on the left. The wrist rest is soft and comfortable and is permanently attached so it won't move around. The keyboard's generous size might be too large to fit some under-desk keyboard trays.