Agurudev, go out and stand by your bike. Take one foot, and push down on the peg. Notice how it moves around? I did not like that feel, at all. The bike always felt like it was moving around, as if I were not well attached, and never could quite figure out was happening beneath me.
The solid mount rearsets stop this, and you get much more feel of the bike. Plus, the pegs sit lower because they are not rubber topped. This also helps with feel, as well as opening up the riding position. I The z1000 has the same frame and its pegs are solid. Maybe some more vibration, but maybe not. I never noticed much of a change.