Ofsted has provided ammunition for both supporters and critics of academies. Of 16 academies visited by inspectors, four have been criticised while the verdicts on the rest have ranged from satisfactory to good.
Eight of the 16 academies to receive Ofsted reports and monitoring letters have done so in the past two weeks.
The London academy, in Barnet, was praised by inspectors for the exceptionally good progress of its pupils.
They said the 1,260-pupil school had raised standards in one of the most deprived areas of the country putting it in the top 5 per cent of schools in England when prior attainment is taken into account.
King's academy, Middlesbrough, City academy, Bristol and Walsall Academy were also judged to be good. Lambeth and Manchester were satisfactory and Mossbourne in Hackney, North London was making good progress.
However, West London academy, which caters for pupils from nursery to sixth-form, was criticised for providing an inadequate education for secondary-age pupils.
The latest reports are a boost for ministers following earlier criticism by inspectors of the Government's flagship schools. Last month, Peckham academy was described as having "exceptionally low" standards and the Business academy in Bexley, Kent was given a notice to improve. Unity City academy in Middlesbrough was placed in special measures last year.
The rapid progress of London academy was the result of a strong ethos, high expectations and teaching which is good in two-thirds of lessons. It came despite recruitment difficulties and high staff turnover.
Almost half (48 per cent) of pupils gained five or more A*-C GCSEs last year compared to the national average of 56 per cent.
Nearly half the academy's pupils are eligible for free school meals, more than a third speak English as an additional language and a similar number have a special educational need.
Inspectors' verdict was delivered in a letter to Phil Hearne, the academy's principal, following a monitoring visit last month.
Lord Adonis, the schools minister, said: "These Ofsted reports show that academies have done an excellent job in a very short time to turn around a history of educational failure in some of the most deprived areas in the country."
"London academy is a great example of how academies are getting results quickly because it replaced its predecessor school as recently as September 2004," said Lord Adonis.