I always considered the Weinmann centre-pull to be good brakes. However, during the boom, we constantly had to educate consumers on their merits, primarily a s a result of their association with Dia-Compe.
During the first years of the boom, the general feeling among consumers was that anything Japanese was 2nd rate compared to European. The Dia-Compe clones were on virtually every Japanese bicycle and initially were considered inferior, simply because of their nation of origin. The similarity to the Weinmann centre-pull get not escape the consumer and many considered to be a rebadge, inferior, Japanese brake. We were constantly telling prospective buyers that the the Dia-Compe were the copy and that the Weinmann on the Raleigh Grand Prix that they were considering was a quality, Swiss product.
The other thing that hurt Weinmann was the other half of the reciprocal agreement, the Dia-Compe safety lever. These first appeared on Dia-Compe and Weinmann brakes and consumers immediately noted the poor stopping power compared to MAFAC and Universal equipped bicycles. However, they erroneously associated the poor performance to the brakes rather than the safety levers. MAFAC and Universal didn't adopt safety levers until much later. The average consumer loved the concept of safety levers but not the performance and the reputation dogged Weinmann for a long time as a result. The best performing safety levers we ever had were the Shimano on the Sekine, but this was because the levers were positioned at the factory using jigs to ensure optimum performance.
In our local there was a legitimate performance concern with Dia-Compe on the Apollo models. The brakes were spongy and this was eventually traced to lighter gauge cables. We never had this with the Weinmann on the Raleigh and CCM.
On a head to head comparison with MAFAC Racers and Universal 61, I always considered Weinmann 999 to fair well, with the major drawback being the levers themselves. Safety levers often resulted in hoods not being spec'd and eliminating the most comfortable riding position. Even when hoods were used, they were so hard that cyclists preferred the MAFAC half hood. The Universal were luxurious with their full, soft hoods and had the added advantage of cable adjusters. Weinmann had a nice feature with the dimpled levers that resisted hand slip in the rain but few rode in the rain and MAFAC had lever grips.
MAFAC could outperform both Weinmann and Universal due to the larger pad area and a more intricate design that allowed fine tuning, but this complexity also made them more laborious to set up and they often came out of adjustment as a result. A performance orientated cyclist who like to tinker was more likely to choose MAFAC.
Overall, the Weinmann were quite good, once you ditched the safety levers and installed decent hoods. I'd consider them on par with Univesrsal. They could be considered to be slightly ahead or behind MAFAC, depending on how performance oriented you are and how much you like to tinker.