First some context. I built a studio desk about 6 years ago that has worked well, but lacked much actual desk surface (see photo). My heavy (and old) 88 key MIDI controller sat on a lowered desk surface and I was never able to implement a proper "top" for it. The Headquarter is exactly the same size as my old desk, and as a bonus, matches the style (black metal and walnut veneer) of my storage shelves on either side.
The Headquarter was packed very well, no dings or scratches ( but lots of packing material to get rid of). It was very easy to assemble, I did it myself. About an hour for the desk (taking my time), then another 45 minutes for the keyboard tray. This workstation is very sturdy. While my old keyboard technically "worked", I had to make adjustments that I was not comfortable with. The keyboard tray holding a 50lb (22kg) turned out to be a pain to move around on carpet, my problem, not Wavebone's. In the end I went to my "Plan B", replacing my old keyboard for a nearly as old (by design) Nektar LX 88+, which now allows me to adjust the Workstation perfectly and is much easier to move in and out on my carpeted floor.
On the rack mounts and cable tray: I thought the cable tray might not be enough for my setup, but I was pleasantly surprised to find that it worked perfectly. I use the middle rack space for a power strip, which allows me enough space to store 2 hub interfaces and an ethernet switch, actually reducing cabling. On thing to mention, if you have any rack mount device that is deep and has connections that protrude from the rear (like a Word clock BNC for example, you may not be able to put it in the top rack space. I have a UAD Apollo 8p Thunderbolt that I had to move from the top space to the bottom space as my Word clock Out connection is interfered with by one of the cross braces of the desk. This is a very minor issue easily resolved.
So far I am thrilled with my new workstation, I now can do mixing and mastering tasks with my legs completely under the keyboard tray, sitting comfortably upright with not interference. If you have a very "thick" (6+ inches) keyboard and are tall (I am 6'0") you may be slightly uncomfortable trying to get the height of the keyboard tray right. A tip: When considering the distance from the top of the keyboard tray to the desk you need to measure from the top of the tray to the bottom of the desk, then subtract 7/8" (22.22mm) to account for the metal support spanning the underside of the desk.