I don't agree but not everyone looks at things the same way. As an engineer i think the mk1 GTI is better engineered
Twist beam rear end nothing wrong with that in such a small light chassis. Its only when you get bigger and heavier that a multilink helps more. Remember VW still use it on there small cars.
Twist beam is cheap, always has been.
Multi-link/double wishbones are better, but dearer.
If cost (and packaging) wasn't a problem, then even VAGs light cars (Ha!...still heavy next to the likes of an ITR or early CTR) would use multi-link rears at the very least as it has such a huge impact on the overall chassis performance.
I agree about weight though...that's the key!
Light weight, less than a lotus elise, shells stiff enough if you don't play silly buggers with the shocks/springs or if you do, you need to know what the limits are (BRM did many don't). Never noticed it twist unlike some other makes.
Brakes nothing wrong with the brakes its a journo BS, you look after the rear brakes and there adjustment they work fine. Otherwise they are as the myth says. Just not as over servo'ed as modern numb machines. People use to have muscles 
Nothing wrong perhaps.
Just not as good as a more modern set-up.
That's progress...
Where bodyshells are concerned, still is best. End of.
From a still base, all else hangs and stays where you put it.
I have read the design papers on the EA888 and control systems of the mk5/6 and the mk1 is far better engineered. The mk1 GTI was designed by engineers, the mk6 was designed by committee and accountants.
An engine is an in-efficient old hector.
Anything you can do to improve the efficiency, is a good thing....especially if you can reduce wasted energy (unburned fuel) whilst doing so....and to improve the efficiency requires engineering progress.
So explain how a 8v 1.8 is more efficient (or if you prefer, 'better' engineered) than a 16v FSI engine running full computer controlled management, with variable valve timing and a turbocharger etc?
More power and less emissions = better engineering in my book.