If you preselect some objects in AutoCAD 2012 and hold down [Ctrl], then the objects will move a bit if you hit an arrow key. Great, cool!
Exactly how far do they move? Let’s try it, shall we. First time, the move was about 4.5565 units. Zoom around a bit and try again. This time, it’s about 11.6677 units. Zoom around a bit more and it’s different again. And again. What’s actually happening is that the Nudge feature is moving the objects by 3 pixels. What? Since when has AutoCAD dealt with object location in terms of pixels? Since 2012 came out. Does object snap help? No. So you can expect to see a bunch more drawings that have been eyed in. “Looks near enough to me!”
OK, so you can turn Snap on and have the objects nudged around in a more rational way, or just ignore the feature altogether. But that’s not going to help you clean up the messy drawings that are now going to come your way for editing. Of course, some people have never needed any help to make messy drawings, but those that needed a little nudge in that direction have just been given it.