I have, over the years, had them all...single rear drive, dual rear drive (positraction), fwd, fwd with stability (front axle locking), AWD, 4WD and full-time 4WD (Jeep QuadraTrac I and II). 4WD is fine, but, you have to shift to get into it, and not all 4WD units are on-the-fly shift enabled. By the time you know you need it, in some instances, it is too late, other times you have to either slow or stop to enable it and then continue on and then slow or stop to disable it when the roads firm up (most 4WD units lead very short lives if run on dry pavement). When the roads are variable, dry patches with slick intermixed, 4WD is less suitable for those changing conditions.
The best in my book was the QuadraTrac system. Full time 4WD...all the time. My Jeeps have been like tanks; they just go, no pausing, no slipping, just traction if traction was available. For most of us, though, the modern AWD system is quite sufficient. Lighter weight when compared to 4WD systems and no thought involved. You get into a slippery condition where traction for each wheel is variable and constantly changing and the AWD is there to get you through the problem by putting the majority of the torque on the wheel that has traction enough to use it and being able to change the driving wheel almost instantaneously and seamlessly. You don't have to think about it, you don't have to plan around it, it is just there when you need it automatically, most of the time, you don't even realize it is happening. If you don't need it, the JD's AWD defaults to a standard FWD system for fuel mileage. Is it off-road suitable? No, 4WD is much better at rock climbing, mud, etc., but, most of us don't off-road (I have a 4WD truck for that) and most of us stay off roads that 4WD would prove more suitable than AWD. Having had both, I've not found a road condition that my AWD hasn't handled as well as my 4WD Commander did. Have there been roads that were better left to 4WD? Yep, but, when the roads are that bad, I stay off of them until they are plowed or the depth is 6 inches or less and my AWD is quite suitable at that point. I got rid of my Commander (full time 4WD) because of my confidence in the MOPAR AWD system and its ability to go when I need to go, tempered by my own sense of when to be on a road and when I should be parked at home. Shouldn't cause any driver confusion; the driver doesn't have to do anything (unlike 4WD) or plan ahead; they just have to drive with a modicum of common sense and the car's system will handle the "go" part. I know I don't even think about it; it is there when the road condition warrants it and I don't have to do anything to make it happen.