Yes, I have used the 35 RF for over a year. I have the 40 Sonnar as my primary lens. Because I don't use portrait length all that often, I opted for the CV 75/2.5 as my longer lens rather than the more expensive Rollei 80/2.8 Planar. I love the compact size of the CV 75 Heliar & it is very sharp. Because it is a longish 75 (Pop Photo measured it at 77 mm.), it works very well with the 80 mm frame lines. Pop Photo also found it's maximum aperture to be not quite f/2.5 but actually f/2.7. When I look at its lens design on the Cosina website, it looks to me to be a copy of a Zeiss Sonnar, so it could just as easily be called an 80/2.8 Sonnar, which is probably what it would have been if it were made by Zeiss or Rollei.

Cheers,
Bill