Sigma has a real winner here. This lens is unusual for a 50mm as they are typically rather small. This one is much larger than the Nikon/Canon variants (other than the Canon 1.2 of course!!!). But still, it is not THAT big. Feels real good on my D700. I also LIKE the 77mm filter size as that is somewhat of a standard filter size in Nikonland and I have them already! This compares favorably, for example, to the new Nikon 50 1.4 AFS as that takes an unusual filter size for Nikon shooters (58mm).Anyway, this lens is solidly constructed, as I would expect from a Sigma EX lens. It also focuses quickly, accurately, and quietly, with the well implemented HSM focusing system that Sigma has developed. It is also sharp, acceptably-so wide open, and razor sharp stopped down a bit. Nice bokeh. Combine this with a D700 or D3 and you have perhaps an incomparable low combo! You cannot believe the shots you can make with this lens and those Nikon bodies in very dim light. I like how the lens handles. Jeez, I just like everything about it!!! No need to go Nikon for this lens type. Very very highly recommended... 

Question: How are the results?
Answer: Sigma has a real winner here .