This lens is terrific!
I took possession of it this past week and have been shooting with it the last few days on my M9. I’ve already posted some images here, here, and here.
I can’t believe what I’m getting.
On the downside, it’s true that you’ll get the infamous “red edges” (peripheral colour shifts) in many images with this lens. The red edge phenomenon is a known issue with wide angle lenses when mounted on the M9… literally, the edges of the photo are coloured red:
This happens because light passing through wide angle lenses strikes the edges of the camera sensor with a steeper angle of incidence, causing colour shifts.
Compounding the problem is that I haven’t even tried assigning a Leica lens profile to the my Voigtländer 15mm, which would result in some (software) correction of the colour, as well as the vignetting that is also present. Why haven’t I assigned a profile? I don’t mind the vignetting (I often add it when post-processing anyway), and I’d rather work around the colour shifting. Now, if I was primarily a landscape photographer, this issue would be most bothersome. Something to consider if you’re contemplating getting this lens.
Stay tuned this week for more images.
—Peter.
Prosophos 
I used one of these lenses when I still had the M8. And even though I couldn’t fully enjoy the quality of the lens (because of the smaller M8 sensor), I really enjoyed shooting with it!
Thank you Sander.
Yes, the shooting experience on the M8 would be identical to the M9, but the output would be somewhat cropped (though still wide).
On the positive side, you likely didn’t have to deal with “red edge” issues or heavy vignetting (I accept these limitations on the M9 and work around them).
No, I didn’t had to deal with those issues indeed!