I just bought a CV 15mm Heliar from a member here, great lens and like the 75/2.5 and 28/1.9 I have... great quality.
First, this lens is really, really wide. When it first came in I looked through the finder and thought whoa! It turns out the lens is even wider than the finder, the finder shows a 93 deg. angle while the lens is 110 deg., which means for "street" photography your gonna have to be really, really close to your subject (so close you'll probably being sharing a smoke afterwards
I ran a roll through it today, most shots were too far away, but at f11 everything was in focus. Flare was very minimal even with the sun in the corner of the frame. This is going to be a fun lens to use.
Here are a few samples from today, I'll have to get closer next time...this means I'll need breath mints I guess