Many Autocad users never turn on the Snap Mode because we generally do not draw on a grid. You must admit with Object Snaps, Polar Tracking, Temporary Tracking Points and Tracking, you probably have no use for running snaps. I know one other characteristic of Snap Mode that really bothered me was that is was on all the time. Of course you could press the F9 key and toggle it off when it prevented you from selecting a particular entity.
Autocad 2012 has given new functionality to the Snap Mode function that will give snap snobs like me a reason to try it again. The big change is now Snap Mode is only effective when the command is requesting a coordinate point selection from the screen. During commands when coordinate picks are not needed or when executing commands that do not require screen coordinates, the Snap Mode is turned off automatically! This feature makes the selection of the diagonal line a breeze even with Snap Mode on.
Other enhancements include the ability to diaplay the snap grid as a X,Y grid or as a dotted grid which is used in earlier releases of Autocad. You can specify the grid display type in three Autocad environments, Model Space, Paper Space and Block Editor.
Other enhancements include the Adaptive Grid check box. When checked the minor grid lines disappear at higher zoom levels and re-appear at lower. This is similar to earlier versions of Autocad but when the switch is unchecked, the minor grid lines remain visible until they cannot be displayed at the current zoom level.
The Display Grid Beyond Limits switch makes it very easy to expand your grid display without having to execute the limits command and change your template default limits.
The last point I wish to mention is a cosmetic or visual change to the grid. Autocad uses the color Red for the X-Axis and Green for the Y-Axis. If you desire to apply these colors to the grd, you can find the switch in the Options dialog, under Display, Colors. You can also apply these colors to you cursor and Autotrack vector lines.
Autocad 2012 gives me a new respect for Snap Mode, I hope you will have a new appreciation for the tool as well.