Well, I can immediately see two things which might impact the outcome:
If you didn't use a mixer, then the sugar wasn't beaten. That will change the finished cookie..chewier, I think?
And letting the dough sit overnight also impacts the dough. I don't know the exact result of that...dissolving sugar? gluten relaxation? just that the creator of "David's Cookies" said that was a necessary step for their cookie dough.
So...just in case these turn out to be "The Cookie"...remember that you did those two steps.