Well, when the British have decided to stop impressing Americans in 1812, why should the Treaty of Ghent cover that?
True, the end of the war in Europe made impressment a moot point during OTL's negotiations. However you raise a good point. Effectively TTL's treaty would be little different than OTL's Treaty of Ghent (perhaps with a few extra benefits for the Americans, non-territorial of course...). The only difference would be that it would be several years earlier and abort OTL's useless bloodshed.
Such a treaty would also have an interesting effect on the development of Upper Canada. In OTL, prior to the war, the cultural character of Upper Canada was largely American due to the policies of granting free land to all applicants, most of whom happened to be American. Given the American occupation of Upper Canada in TTL, coupled with America's "victory" one might see a significant population shift. In OTL, those areas of Upper Canada that were occupied by the Americans saw an exodus of "collaborators" following the American's retreat and the end of the war. With a prolonged American occupation of Upper Canada, I'd imagine that such a phenomenon would be writ large in TTL across the whole region.
The exodus of "collaborators" from Upper Canada, might put the British in a tough spot in TTL. Perhaps, in an effort to restore good relationships with their Native Allies and to ensure the defence of the rest of Upper Canada, they offer Tecumseh a chunk of what would become Southern Ontario (around Windsor) to create an Indian Confederacy? Though this would in no doubt antagonize the USA, proper negotiations and guarantees could lead to America accepting such a prospect in the aftermath of TTL's War of 1812.
Another thing to take into account would be that in TTL there would be no Hartford Convention, No burning of Washington DC, No Battle of New Orleans. The American experience would be undoubtedly altered...