Posting on the official Naughty Dog blog, community overlord Arne Meyer relayed information from game director Justin Richmond, who's able to speak more clearly on the technical performance of Drake's gun. "Aiming is identical to Uncharted 2 - we took a look at the values side by side. We did adjust the sensitivity to be MUCH higher in Uncharted 3 to give you a more precise feel. With Uncharted 2 it was pretty much guaranteed you would aim in one of the 8 directions and it was hard to deviate from that (imagine it being almost like a traditional 8-way arcade stick)." According to Richmond, "With Uncharted 3, you can deviate from the straight path from each of the 8 directions much easier and more precisely."
So, contrary to some complaints, sensitivity has gone up. However, enemies also change positions faster now, "which changes the flow of gun combat as well, from what you were used to if you're coming off fresh from Uncharted 2." We've had this same problem at Joystiq HQ, and believe that aiming assistance might be a tad too magnetic, slowing your reticle down when it gets near an enemy.
The most interesting part is that the gunplay in Uncharted 3 has been adjusted in another significant way. You might not have known it looking at him, but Drake's shots used to come out at weird angles. "In Uncharted 2 the bullets would leave the barrel at a pre-set deviation when you were aimed in," says Naughty Dog. "What this means is that the bullets would not fire straight out of the barrel all the time -- they could come out at an angle. Therefore, you could have a target clearly in the reticle and still miss it by a wide margin." In the sequel, "bullets now fire straight out of the barrel 100% of the time," though you need to adjust for recoil.
There's a question about which ultimately takes precedence: the informed explanation rooted in data and design, or the more nebulous discomfort of an aim that just feels ... off?