In terms of recruitment and results, City have done pretty well this season.
The arrival of Sergio Aguero and Samir Nasri has helped transform the club's dour image and though they have suffered a couple of setbacks on their travels recently, the Blues have moved into a three point lead at the top of the Barclays Premier League.
Mancini is keen to bolster his squad even further during the present transfer window, although it may take the departure of Carlos Tevez for that to happen.
Yet the Italian concedes there is still one area where his team are inferior, the great unknown about how they respond in the most pressurised of situations.
"If you want my opinion, Manchester United are the best team in England," he said.
"Maybe not now because they have six or seven important players injured.
"But they have a strong team with a strong mentality and they are at the top."
As Mancini said very similar things about Chelsea last term, only for United to win the league, either his comments should be taken with a pinch of salt or he is a lousy judge of opponents.
However, the former Inter Milan boss is correct in stressing the differences between what he has managed in two seasons at City and what Sir Alex Ferguson has created in 25 with United.
"We can't be like them in two years," he said.
"They have had this mentality for 25 years.
"We can improve if we continue to win, if we win the championship or other cups. We started it last season. But in two years it is impossible."
They have inflicted some pretty hefty damage in that period though.
Last season's FA Cup semi-final win was seismic in that it paved the way for the club's first silverware in 35 years.
And then in October came that staggering 6-1 triumph at Old Trafford that sent shockwaves around the world and leaves City on the brink of a hat-trick of derby victories for the first time since 1969.
"It was important to beat them in the semi-final last year and it was important to beat them at Old Trafford," said Mancini.
"It was not the 6-1, they played for 40 minutes with 10 players, which is very difficult. It was important because it was a good performance.
"We played very well away from home."
It was part of what has been widely acknowledged to be a pretty good season by City so far.
Not that Ferguson is acknowledging the thrilling manner of their performances.
The Manchester United manager claims Tottenham have played the best football so far this season.
Mancini just chuckles.
"It is difficult to say your neighbour is playing better football," he said.
"Tottenham can win the title. They have done a fantastic season until now and in the next four months, I don't know.
"But, for now, we are playing the best football in the Premier League."
Asked to name any United players who would get in his present team, Mancini skirted round the issue and instead listed Nani, Rooney, Giggs, Ferdinand, Carrick and Valencia as "good players" whom he admires.
For all United's present injury woes, all should start on Sunday, merely whetting the appetite for a contest which can now match any derby in the world, including Milan, even though it will take quite some time before City have a history like Inter's.
"In every city where there are two teams, the rivalry is very intense. Rome, Milan, it is strong everywhere," said Mancini.
"In Milan it might be different because for a long time Inter and Milan stayed at the top. They won European Cups and championships.
"But, remember, before I arrived at Inter, they didn't win for 19 years.
"For Inter this was very difficult because Milan won a lot of trophies.
"It is the same situation here.
"It is clear Manchester City doesn't have Inter's history but they have also started to build a new team, a strong team and has got to the same level as the other one."