The 4WD Compass is on demand AWD with a 4WD lock lever for manually splitting the torque 50/50 front to rear when stating in deep snow, sand, gravel or other low traction conditions. See the jeep explanation here:
Click on "Get Ready" and then "see how Jeep 4X4 systems work", then select Freedom Drive I.
The difference in the shifters: the regular CVT2 has "D" and "L", "D" is just like a regular automatic with an option of using "L" when necessary; the optional AutoStick also has a "D" for normal driving conditions but lets you select predetermined ratios 1 - 6 for special driving situations, ie; performance driving, engine braking on hill descent, it's also used for snow covered hills where you might not want a gear change. It's a handy option but under limited circumstances.
They are GREAT in the snow, even with the not so great tires that the factory puts on them. Go here for the Snow pictures and info: