I hesitated to bring up Dr. Porsche's unique dual trailing arm suspension because I'm under the impression it was one of the few suspensions that didn't change geometry through its travel. I loved the suspension for its ruggedness and it's almost total lack of needed maintenance. It never broke, and I did some stupid stuff in my first car, a '57 Karmann Ghia. It had the 1100cc 36hp which I likened to an old Jeep. It had tiny valves and intake manifold which made it impossible to over rev and hurt that way. I wanted a TR6 so bad as my first car but my dad found the Ghia(bless his heart). It was the parts managers car at the local VW dealership. Mechanically it had all the running gear rebuilt and after several years of trying to blow it up i came to have grudging respect for it. I could not out run anybody on a straight away but there were no American, very few other cars that could hang with me in twisty roads. The old Ghia and the 356 Porsche were both made in the Karmann body works and were in the same parts book at the dealer.
I had friends who did what we called "round and round" on a local dirt race track. I think it was something like Sportsman class? Dunno, it was all "big iron" American and just not that interesting to me. I saw how they engineered a suspension to basically want to only go around a left turn as that's all that oval was. To me those crazy guys who did those rally's across Africa etc.....now that was some driving, but to each his own.
You don't mention what I always thought was what made Dr.Porshe's design a cornering machine was the fact it was rear engine. I can't remember who said it but it went something like " the difference between under steer and over steer is which end of the car goes through the fence when you don't make the turn". Once I got used to under steer I just hated fighting to get around a corner with a front engine car. It's one of the reasons I never owned a American car until we bought the Volt earlier this year. There is no denying they go down a straight road like gangbusters, but sooner or later you gotta turn, if not to dodge somebody. And that's when that feeling of being on rails from too much weight ,front engine along with too soft suspension w/body roll and detached feeling of the steering just made me feel like I was not really in control.
VW's like all of Dr. Porshe's designs were all about hp to weight. You mention the 1200, what we called the 40hp. That and my last VW, my '66 1300 bug, were my favorite engines for just get you down the road and last forever without dropping a valve. I was able to blueprint my 1300 because I was a "free agent" at automotive school and it was the only engine I drove from one rebuild till I went through it again at 120,000mi. Yeah, thats not a misprint. And it didn't blow, it wasn't even using oil, I just got scared. There was no way I'd ever drive a 1500 or 1600 that long without doing a valve job. Anything over 50k you were a ticking time bomb. It was just too hot here and they were being made to run too lean for smog.
You mention the 1500 dual carb, there was only one year, the '66 Type III. We had one, it was my mom's car and got it new in '66. I think it was rated 60hp but it was the "suitcase" engine w/the axial type cooling fan and heavy as hell and long rear end overhang making very rear end heavy and scary in a turn. So weight to hp wise it sucked compared to a loose old 40hp. And because of the throttle linkage and crappy Solex carbs they were almost impossible to sync and get to run good. I realized much later it was because the throttle shaft hole through the body would get wallowed out because of the huge return springs making them leak vacuum.
Those old 40's always ran so good right before something would finally let go. We used to have those come through the shop all the time because people thought they wanted a 1600 or 1650 so they would sell them a 1600 and we'd keep the 40hp for banging around as a shop vehicle.