Asking how much better is a lens than another lens is kind of like asking someone how many angels do they think can fit onto the head of a tailor's straight pin. Every one will come up with a different opinion.
I have only owned two Rollei 35S and two Oly RC so my testing is limited to this small sample. The winner is----------------the Rollei 35S Sonnar!!
The RC is about 1/5 the price of the Rollei and I don't think the Sonnar is 5 times better than the Oly lens. If you want a rangefinder camera the Oly wins hands down, since the Rollei is a scale focus camera.
If money is not an object I would definetly get the Rollei. It is a little funky to get used to, but it grows on you.
One's skill is never complete, one's knowledge is forever lacking, one's taste is invariably altered, one's opinion ever subject to controversy. There is a complete and constant urge toward improvement...
"Good Judgement comes from experience. Experience comes from bad judgement."