Easy to operate desktop elevator with enough space on it for my laptop, a backup hard drive, a USB port multiplexer, my phone - and space to spare. Raises itself when you squeeze the handle on the right. To lower it requires a little pressure, but not too much. I use it without the keyboard tray, which is fine. I've raised my chair to its maximum height to accommodate the extra height of the airLIFT PRO above the desktop. I also use a MotionX rocker board to stand on - I find that more comfortable than standing just on the floor.
Quality seems to be good - I've only used mine for about a month, but don't see any problems arising.
The one slight problem is that it doesn't have preset heights, but I use it fully up or fully down, so this isn't a problem for me.