I don't know, Daniel. All of the controls on my R90S require more effort than on the R65. The Dell'Orto slides have strong return springs; the front brakes work well but have no real feel (they're like squeezing a brick); and the clutch, which has a relatively new cable, is the heaviest of any of my bikes.
Regarding getting rear ended: it's not a likely scenario, at least according to the "Hurt Report", the most comprehensive study done in the US, but completed back in 1980. If I recall correctly, only a few percent of the 900+ crashes investigated were rear enders. But times change and there's no doubt that the traffic is heavier and more distracted now than then.
I watch my mirrors and don't shift out of gear until I've got some protection back there.