There is no doubt that the "Glorified bathtubs" , (Kristi) as you reffered to them, were poor machinery. The most significant supporting evidence of this is the ratio of the currently running machines to the number produced. ST4's have a much higher ratio. Snow tracs that were built before Kristi's even came into existance are STILL RUNNING. I'll rest my case there.
The synthetic oil cooling properties are very accurately researched by none other than VW Guru Gene Berg. They did in depth testing and wrote extensively about it in one of their service publications. Their testing showed a one degree heat loss of heat carrying capacity. This was under some of the most severe racing conditions, with VW Air cooled engines that had been "hot-rodded", or modified and built up to the limits of a VW Block. I'm still a fan of synthetics. One degree of 'lack of cooling' is not enough for me to get excited about. The advantages, Engines that last twice as long, plugs that last 3 times as long, and engines that start at 35 below with no crankcase heater overide the heat loss issue for me.
About the time I was putting air temoerature sensors all over the engine and engine compartment on ST4's and doing my own personal little study, Ron Hoffman, a fellow ST4 owner in Washington and big Gene Berg fan, pointed out the study to me. I promtly got a copy of Gene Berg's workshop manual and read it cover to cover.
In North America, the two preiminent all time GURU's of VW's would be John Muir, of "Idiot Book" fame, and Gene Berg, and later his son. John Muir more catered to the VW Hippie of the 60's and the home/back yard mechanic. Even though he has been deceased for some years he would be considered a legend in the VW community. First Editions of the Idiot Book are prized collector items. Fully half the VW mechanics in the US quote him regularly, and have an old greasy copy of his book handy. Gene Berg and his son took HIgh performance and Racing VW's to entirely new levels. Some of thier research was possibly more in-depth than Volkswagon of Germany engineers and certainly in line with Porsche Engineers.
The defense rest.