Interesting. I've noticed the front getting power while slipping in 4A but I would by no means call it clunky. In fact, I'm rather impressed with how well it works all things considered.
I can feel it engage and disengage. A little jerk when it does because the surface has to be slick enough to allow some slip between front and rear or it'll make itself felt in turns like driving in 4x4 High when the road is dry.
The 1990's AWD system wasn't noticeable. Always "on", always there. Nothing electrical to fail. Sending power to the front is faster with it because it's already sending a little forward all the time. Doesn't take much rear slip for the viscous coupling to grab.
It could be abused if one treated it too roughly. I rebuilt a transfer case on a 98 Mountaineer. The prior owner had somehow managed to bend the input shaft and the viscous coupling didn't have a healthy color. The chain was pretty loose too. So it got a new shaft, new chain, new bearings, and a rebuilt coupling.
Where this style of AWD doesn't work is off roading where you need the front traction *but* the back wheels have too much traction. They have to slip a bit first. Some years of the Oldsmobile Bravada had a similar AWD system and I've seen plenty of pics of them nose down in a ditch, stuck there because the rear wheels had too much grip to get full power going to the front. But for winter driving on snowy or muddy roads it's very good.