Let's suppose that Benedict Arnold had received his just recognition in helping to win the Battle of Saratoga, and that he had not turned against the American cause while he was in charge at West Point -how differently would events had transpired had we still had him on our side?
I predict he would've ended up dying a Nathan Hale death and he would've been known as a Great American Hero. We would've gained momentum due to his execution at the hands of the British and maybe have accelerated the end of
hostilities. However, due to the nature of politics the war might still technically end as late as it did IOTL.
This is of course wild speculation.