How much of Cosina's output is original design, and how much is simply remakes of classic designs for the nostalgia market?
Most of Cosina's design are original designs - 12f5.6/15f4.5/21f4/25f4/35f1.2/ 50f1.5,/ 75f2.5,/ 90f3.5. The rest of the lenses are variations of common designs from Voigtlander/ Leica/ Zeiss etc.
There are only so many ways of routing light through a lens and be able to make it at an affordable price. At the moment Leica has a couple of unique designs, 21f1.4/24f1.4/50 f0.95 and the 50f1.4 Asph/75f2 Apo Asph. Problem is that those lenses are very expensive and also heavy.
There tends to be a habit of looking down on Cosina as a "wannabe" - trust me. Leica would love to have the knowledge that Cosina has in optics and manufacturing as well as their designers.
Lenses like the Heliar 50f2 and 50f3.5 are upgraded, modern versions of classic designs - as are several of the "standard" designs from Leica - many of which started with Zeiss.
There are few truly original designs out there - again it is a way of balancing performance and price - and that is a race that Cosina leads right now!
I have VC, Leica and Zeiss lenses. I tend to shoot with them all, pick out favorites and use those for most of my stuff. It is about 1/3 VC,1/3 Leica and 1/3 Zeiss.