I use this sideboard with my 19 inch mixer rack. I own a big and high rack with wheels and love to have the opportunity to roll it into the location, place it everywhere I want and use it.
Before I had this sideboard, I always had to take an extra table with me, put it beneath the rack, just to have a small space to put on my iPad or Macbook. With this Sideboard these days are over; I can just assembly it to the rack and got enough for space for an 15 inch Macbook to record the show. And if you do not need something to record it is handy as well; just to use it as a mobile office, with all the documents (Input lists, job info, and so on) you need.
I am very happy with this Sideboard because of its handiness. These are the things which make my life far more easy.