Germany loses faster. There were many instances where Hitler overrode the German high command that he was right and they were wrong (going for Kiev before Moscow, for instance). Some of these instances were more luck then insight, but that does not change that it contributed much more to success then the generals own ideas. The one time he totally delegated the making of a war plan to his subordinates, the result was Kursk.
Part of the reason Germany got as far as it did was because of Hitler's "meddling", something the surviving German generals after the war pointedly ignored because they wanted to simultaneously disassociate themselves from him and wash the stink of defeat from themselves. So they wrote book after book blaming everything on dead men, who being dead were in no position to rebuke or contradict them, and in doing so deliberately obscured the very real contributions he actually did make to Germany's success.
They even blamed some things that were really their own fault on him. The halt order at Dunkirk is a classic case-in-point: the order was not actually Hitler's, it was Gerd von Rundstedt. Hitler merely just happened to be there to give his stamp of approval while consulting with Von Rundstedt on a number of matters, a fact that Rundstedt was able to use to pretend that he had no responsibility for the order he drafted and issued.
Hitler's core belief that war offered Germany her best (only) chance of becoming the dominant world power was madness but there's evidence he knew it was a huge gamble. He was just convinced of his ability to beat the odds and didn't care about all the death and destruction such an attempt would result in. Once that core position is accepted, Hitler's actions show he understood the dangerous game he was playing and the tight timelines he was under. In contrast, very few German generals seem to have fully appreciated the situation. the orthodox view of the German officer class was that Germany would have to regain her power and position through offensive war against her neighbours, they dissented greatly on the specifics - namely, the "when." OKW wanted to delay war until some time around 1945/46 when they felt they'd be fully prepared.
Hitler called them a bunch of old women with no strategic insight, and overrode them. And he was right. What OKH had failed to realize was that, while Germany had stolen a march on the Allies with early re-armament, France, Britain and the Soviet Union were catching up rapidly while Germany's stocks of strategic resources and her ability to sustain high rates of production was beginning to fall. By 1941 the military balance would have grossly favoured the Allies and that would only increase as the years went by. If it was to be war, Hitler had to strike fast while he still had the advantage.
The simple problem with "letting the generals run the war" is that the generals lacked Hitler's strategic insight. And the fact that Adolf Hitler was ultimately a better strategist then the German general staff is a pretty damning indictment of their strategic skill.