But what's that you say? We haven't addressed the 3.5" barrel? We should. While it has only a slightly longer sight radius than the 3" barrel, it will have a full stroke for case ejection.
As someone who looks at revolvers as a defensive tool to be worn on the hip, I have to note that the longer the barrel makes for a longer draw. If you're trying to pack a revolver in a strong side high ride holster, 3" to 4" is about as long as a man would ever want to carry, even with a forward cant. Anything longer requires a drop holster. (Trust me-- I have a 39" sleeve length, and wear high ride regularly, but it feels awkward as heck to draw my 6" Officer's Model Target from even a semi-drop) Frankly, at 4" or longer, I think that cross-draw is the way to go.
With pointability, it's all about the individual revolver. I've a friend who has a 4" Model 10 with a bull barrel that points as well as some M10's that I've handled with skinny 6" barrels. I've handled some nicely-gripped shorter revolvers with good sights and triggers (I'm thinking of a family member's M27) that I would have sworn were longer barreled, because of the large frame and easy handling. Interestingly, the mass of the cylinder makes a significant difference in the pointability.