Maybe I just have a soft spot for Duncan, or maybe because he's the only human being alive I can imagine who has the "heft" of The Kingpin, but I liked him well enough in this. Speaking as a guy who can appreciate true beefcake power, I fully believe that Duncan could break a mans neck with one hand. The man's full on beef blow out bonanza.
I agree with the comments above - they should have made The Kingpin appear to be more of a nice guy on the outside who hides a much darker side instead of a cold-blooded badass - but I liked Duncan well enough in the role too. Physically, I could believe that he would have no trouble tossing around Daredevil effortlessly, as he does in the final confrontation...and, despite the fact that it's hard to look past how nice and cuddly MCD seems, he does have some menace in that voice of his.