The last Canons, including the 50/1.4, and Summicrons are gauss lens designs. These are the first shots I have developed and scanned from this lens and I have to say that the first thing that came to my mind when I saw them was that they are similar to Summicron images. Considering that it is faster, has better coatings and I bet sharper at f2 than a collapsible Summicron I think the Canon is a winner. It is much bigger of course. I think will reserve comparing to my DR until I shoot that lens a little more. The DR is wonderfully made, so is the Canon, and seems to have some great character too. I think that is where the difference will be. Not so much which lens is sharper or "better." The Canon is faster and both lenses will have a different character. It is to the user to decide which is best.