Tumbler you would be wrong. With Auto Aim 2 things happen on a console game. 1)the targeting reticle will automatically jump to the nearest target, when the targeting reticle is near it. 2)The Targeting Reticle will also 'stick' to target as well.
The reasons for this is to make up for the slow response time and not so precise controls of the gamepad.
With a mouse and keyboard the targeting cursor does not automatically jump to nearby targets near the targeting reticle, nor do they 'stick' and follow the target as well.
As for PC Moniter vs a Wide Screen TV, depending on the distance you sit from the TV and Moniter one may be smaller then the other. But then again I can hook up my 360 to my Wide Screen HD LCD Moniter (and cheaper) with my 5.1 sound card, and still be playing at larger res then my TV.