I think as far as looks go, that the unfluted cylinder just looks better on the gun. Adds to the lines of the gun if you know what I mean. Practically, both work fine in the gun and so far no problems.
I find the Colt to be a very, very well balanced gun to hold compared to the New Army and there seems to be a bit extra room to hold it with large hands.
Also for the people that have that eye for detail, you can see that the front sight on the New Army has been filed down to raise the POI. And it shoots pretty well spot-on now.