Not exactly correct. Honestly not meaning this offensively at all, either way is fine. But have you done any long rides on a road bike? If not, try it and I think you'll understand where I'm coming from about the comparison and wondering if MTBs have the same effect. When you're riding a completely ridged road bike with narrow 100psi tires on concrete and you're leaned over and more of your weight is on your wrists/hands and you're on the seat the whole time, it's totally different than heading down a hill on a trail standing up. From what I've ridden so far, I'm liking MTBing much more than road biking and actually find it less jarring than road biking in general. When you go down a steep descent full of rocks standing up with a kind of loose absorbing posture, its more just large bumps that flow more. ...hope that makes sense. When you're on a road bike, just hitting a series of cracks in the sidewalk can send vibrations up your wrists and spine that are sometimes uncomfortable.

I'm wondering if a stiffer frame MTB will cause more of that vibration than a not as stiff frame, or if all mountain bikes are going to be fairly similar to the one I'm riding now in that sense.