Here's a full review of the 14-24 on my 1DsIII. Many people have a lot of questions regarding the 16-9.net adapter (including Mr Reichmann), the way it works, how versatile it is in the field etc so I have written an in depth article about how to use this lens, not a comparisons article, but one with considerations and questions answered that may or may not be relevant to you. No graphs and charts, there are many of these already on other sites.
I just got lent a 21mm Distagon that I am going to compare this week so look out for another one very shortly.
Any comments about the review and these pictures are always gratefully received. Here's two shots I took with it last week.
This is a blend of two exposures taken at 21mm f11

This moonlight shot was was a straight shot taken at 24mm @ f4