A 24" barrel will shoot exceptional patterns.  I myself have always liked longer barrels.  But that is what I was raised on shooting.  But yesterday I witnessed one of the best patterns I have seen with my buddy Mark and his 24" barrel 835 and the Pure Gold .670 choke I gave him shooting some of my Hevi-13 3" Hevi-13 1.75oz #6 loads that I gave him.  234 shot in a 10" at a taped 40yds.  It don't get no better than that.