To an extent, one bloody conflict is very like another, but there were some striking points in the narrative. First off, that the British came very close to losing, several times; had the Indians been just a little better organised, they could have taken the besieging British force from the rear at their leisure, or indeed crushed them when they finally entered Delhi at the end of the siege. This would have needed better leadership than Bahadur Shah Zafar and his sons were able to provide; but not very much better. My father always used to say that armies in general are so badly run that it is fortunate that they usually only have to fight other armies, which tend to have exactly the same problems.
Second, it was very interesting to see how a complex ethnic conflict, with Muslims and Hindus on both sides, became simplified by British commentators in the immediate aftermath as a matter of European civilisation versus Islamic extremism. There were indeed Islamic extremists, Wahhabists even, associated with Bahadur Shah Zafar; they arrived late and were ineffective and indisciplined, except to an extent in intimidating their own potential allies. But their presence was used as justification for the brutality of the British response, and as the basis for the Western interpretation of the war. Dalrymple doesn't over-egg the comparison with more recent events, but he really doesn't have to.
Third, knowing very little about Delhi and its history, I could still share Dalrymple's grief at the destruction of the old, mixed, liberal, cultural, educated city, a choice partly brought about by the conduct of the insurgent forces but mainly by deliberate choice of the victorious British. It may not be too much to say that the conflicts of ninety years later, and after, had their roots in the sack of Delhi in 1857. A more dignified outcome then could have made for a better transition all round subsequently.
Anyway, I learned a lot from this.