See YOURSELVES on the dunes. A compilation of all the Dirt Bikes and Quads filmed at Silver Lake Sand Dunes during the 4th of July week 2013. By Sand Troopers Offroad Films. Uploads every week.
Go out to Glamis. Drive the two days, camp for a week on a holiday weekend, and really experience it for what it is. Silver Lake is good for a place to cruise around and climb some small hills on your day off, but if you can make it to Glamis once or twice a year DO IT.
I mean it depends on the quad you ride and how you ride. My atv can do roughly 75 mph on flats and maybe 60ish on rough sand or whoops, that seems fast. Also as for taking no skill to ride, atv's take less time to learn how to maneuver but ones you know how to ride one you can keep up with anything.
Hurts a lot harder to wreck, they come at you if you flip. You can also use them to go hunting with, even a raptor or ltz etc...so I'd say quads are better because you can do more with them