Scirocco Register

A correctly set up pierburg will provide more power as it is a larger diameter than a weber. A weber produces better throttle response because you directly control the second stage whereas the pierburg second stage relies on the vacuum to open it. This has been argued many times but the facts remain the same, more air/fuel in = more power out. Most people use a weber carb because it is simpler to set up and a badly set up carb will produce less power. Just because you don't know how to use it doesn't mean it's worse. And just for the record I use a weber carb on mine.

I accept all your points about the pierburg being fine when I is new and set up correctly, but with a view to performance new vs new the weber would still come out tops. The weber has bigger butterfly's than the pierburg even though the physical size of the carb is smaller so it will provide a performance increase if correctly installed.

Pierburg has 2x34mm chokes, weber has a 32 and a 34. Granted 2mm sing gonna make much difference, but size matters

Honestly? Having run both (knackered and properly set up) I can honestly say that the differences are negligible. The Weber has slightly better pickup in my experience but that's it. It MAY have bumped the BHP but you have to keep in mind that they normally replace 30 year old kit and even then it was barely noticeable, to its credit I did find it easier to maintain and smoother, again this was probably due to the old kit being very old. We're talking about 90bhp cars here, not Bugattis.
Injection cams, four branch sand a decent weber would see you through, failing that buy an injection.