As I look forward to tonight's fourth episode, I have to agree with him on all counts.
But there is much more to the success of Downton Abbey than mere technical excellence behind and in front of the camera.
Like all good period drama, this has a resonance far beyond its own setting. This is Brideshead Revisited for the Cameron-Clegg era. As the political class settles in to the comfortable reality of a country run by the boys (and it is the boys) from Eton, Westminster and St Pauls, so the nation will be soothed every Sunday evening by what Heffer calls "that halcyon period between the death of Edward VII and the digging of the trenches on the Western Front".
There was a scene in one of the early episodes when the newly arrived heir to the estate (he's from Manchester and therefore not quite nop-notch) decides he does not need the services of a personal manservant. In an act of near-revolutionary innovation the clod decides he can dress himself. However, after a quite word, he is made to see that he is effectively doing the poor valet out of a job. This, he accepts, is just the way it is and should be.
No one in the Coalition government is suggesting that a return to the upstairs-downstairs economy would bring a return to full employment (although millionaire Phillip Hammond came close in opposition when he said that paying interns was a waste of public money).
But Downton Abbey's examination of "noblesse oblige" at the beginning of the twentieth century has an undoubted relevance at the beginning of the 21st.
Downton Abbey is a television programme, not a programme for government. But as an expression of the cultural politics of our times, it is every bit as powerful as X-Factor, which immediately precedes it in the schedules.
Did Fellowes intend it as a political commentary? Surely it can't be a coincidence that the paterfamilias at the centre of the drama, played by Bonneville himself, is the fictional Earl of... Grantham.