Agen prop Meeuws, who attended the All Blacks' 45-3 win in Lyon, expects the Kiwis to improve further in the 11 months ahead of their return to France for the World Cup.
Meeuws said: "They are really humming at the moment but I think they can add another 10%.
"We haven't seen the best of this squad yet. Graham Henry will go for perfection next year and, remember, he still hasn't played his first-choice side.
"To make 10 changes from the England game and then spank France like that, well, that's a big call. But there is such harmony in the squad, they are all in it together."
The ex-Blues and Highlanders front-rower claims opponents must be as meticulous as the All Blacks.
He explained: "They study every match their opponents play, they know exactly where to attack teams and it's very methodical.
"Every New Zealand player knows his role exactly within the team structure and opponents have to match them for that before they can think about beating them.
"South Africa are certainly one of the most physical sides out there, but their problem is, they still don't know their own game plan as well as they should.
"They go missing at times and too many of their scores are down to individual brilliance. That won't be enough to beat the All Blacks.
"The opposition has to try and find some weakness in the All Blacks. But they are already almost the perfect all-round team, no matter who is involved," he told The New Zealand Herald.