Welcome to the site, Mike.
You can ignore most of the advice you received on that SN thread.
A standard TT Supra is going to be considerably quicker than your lightly modded bugeye, and in my view it's not possible to make a valuable comparison between two such disparate vehicles.
Both have their good and bad points. My WRX Wagon is perfect for the daily commute and general work use, but it does become rather tiring on motorway runs. On the other hand, my TT is wholly unsuitable for work use, but it's an absolute joy on motorways, long runs (apart from the less supportive seats) and on sunny days when I get the roof off as well.
As a side note, although my Scoob is nowhere near the power of the TT it *feels* faster because the noise, hard suspension etc all combine to create the illusion of travelling fast. In the TT it's all so quiet and effortless that I often find myself going quicker than I thought (or in fact should be ).