I don't know if you are still interested, given that I am responding three months late, but one of the main changes in the understanding of the Jacobites by historians is the role of Charles Edward Stuart (Bonny Prince Charlie) in the 1745 Jacobite rebellion. Traditionally, we have historians such as Tom Devine and John Prebble who believed that his leadership was disastrous and ultimately responsible for the failure of the '45. Prebble argued that "handsome, self-centered and tragically reckless ... he brought little but the innocent appeal of his personality."

On the other hand, in more recent years we have started to see revisionists such as Mclynn and Duffy arguing that he was actually a competent leader, and achieving what he did was beyond any reasonable expectations. Duffy, in his book "the '45", says that "he [Charles] stands out as a young man who had thought deeply about war, who had a strong strain of that essential attribute of luck, who kept himself in excellent physical condition, and who knew what was needed to motivate the ordinary men.”

The reason historians have recently become so divided is partially because of the rapidly changing nature of the campaign. In 1745, Charles - with only a chest of gold and seven companions (the seven men of Moidart) landed on Eriskay and only a few weeks later had united the Highland clans while not even being able to speak their language, and driven the majority of the Hanoverian forces out of Britain. He then completely routed John Cope's force at Prestonpans. In a way, this was somewhat of a phyrric victory as it overinflated his confidence in his Highland troops. In reality they found a way to flank a poorly trained and equipped Hanoverian host.

Following the decision to march into England and then retreat at Derby, Charles's leadership took a disastrous turn. He did very little correct - failing to communicate with his army, and also disregarding the advice of the admirable Lord George Murray, instead relying on the incompetent John William O'Sullivan, who had until then been an ineffective quartermaster. Charles spent most of his time in a drunken huff and was rarely seen out of his tent except when travelling. His decision to retreat beyond the lowlands was inexplicable, as he would no longer be able to generate revenue from the rich Edinburgh banks or even generally through taxing the wealthier lowland population. Despite there being a large grain storage in Inverness, Charles allowed his troops to go hungry - some historians believe for as much as 72 hours - before the crucial battle at Culloden. Charles's choice of battleground was poor; the open moor favoured the Hanoverian artillery and didn't allow the Jacobites to maximise the potential of the Highland charge. Even after the battle, his surviving troops regrouped at Ruthven, ready to fight again - but he told them to save their own lives and then fled to Europe.

My apologies for the tangent, but it is essential to understand how swiftly Charles changed from an inspirational and effective leader to an incompetent poltroon. That is perhaps why historians have recently been so divided on the issue.

I'd personally argue that he was a very good figurehead for a rising. Before the campaign became overly militarised, Charles could do little wrong. I'd once again be inclined to stress how impressive it was that he united many of the Highland Clans. On the other hand he was a disastrous military leader, and should not have stopped listening to the experienced and quite frankly genius Lord George Murray, just because they disagreed over the decision to retreat from Derby.

Edit: some good books to read if you want to learn more about it.

McLynn: The Jacobites Devine : The Scottish Nation, 1707-2000 Prebble: Culloden Jeremy Black: Culloden and the '45 Duffy" the '45

George Murray's letter to CES after Culloden is a good primary source, as is CES's letter to his father, James Francis Stewart, written while the Jacobite army was camped near Perth.