With a sit/stand table I wasn't sure I was going to need a keyboard tray, but this has been a major help. It's really nice to be able to bring the tray up some times, down others, and slide it under the desk when I'm working on something else. The surprise bonus though is the mouse platform. The 6G system has the clip mouse function which is a really nice addition. I can move the platform up or down, as well as closer to me or farther away from me. It's very flexible and a great feature.
The "dial tilt" function has helped my wrist strain. I guess I didn't realize how uncomfortable it was to hold my wrists up all day. I love being able to see what degree my keyboard is at during the day.