Well, first of all, removing the camera from the glidecam without needing a screwdriver... thats the biggest help...
But second of all, it allows you to control the fore-aft balance of the camera a lot easier. I picked up one of these for mine, it works pretty well, and there are tripods you can buy that work with the plate, so you can slide your camera between the two with ease.
http://www.bhphotovideo.com/bnh/controller/home?O=&sku=318567&gclid=CKq6vbmxkr0CFY17fgod4QIAew&Q=&is=REG&A=details