Please note that this is not a scientific "test" of any kind, but for some this might be useful?
I have tried some different options for using Zeiss 18mm f/4 T* ZM Distagon Lens on a Leica M9. The M9 had firmware 1.162. I used Cornerfix 126.96.36.199 and LR 3.5. All photos were taken with M9 on tripod and imported in LR and had same with minor modifications. The Cornefix profile used were created by me.
The conclusion is that for white-out conditions like snow landscapes the only solution for me is Cornefix. The Leica built-in profiles in firmware 1.162 gives accoring to my needs next to nothing improvement when it comes to handling color shifts on right and left hand side.http://flyalf.wordpress.com/2011/11/21/zeiss-18mm-f4-t-zm-on-leica-m9/
Here is a sample pic with CF (yeah, yeah, its usable to compare