I agree with puppy & TN GC about the weight. Heavier is better for both traction and ride. The one area that extra weight is not your friend, is on hillsides when the weight is above the midline of the machine giving you a higher COG.
I'm old enough to remember when cars were cars. Even though suspension technology has moved forwards by leaps and bounds, those old "heavy" cars of the '60's and 70's rode worlds better than later cars, especiallly those like todays full sized so called "heavy" cars do. Is just common sense. More weight will require more force to move, and more weight will absorb more impact before moving.