If it's any help on your decision Nikon makes the glass for Leupold from what I've been told.
So, following that piece of information the glass argument is really a moot point since the glass would be the same

IMO these types of threads rarely provide much assistance to the OP because it ends up being an opinion which is not usually based on TDP (technical data package ) analysis. What I mean to say is that if you aren't reading the specs of each scope specifically and their tolerances then it's just one man's data point or experience.
I say: look through the ones that catch your eye in different lighting scenarios, outside if possible and then make your choice based on what fits your budget and which one looks best to you.
I have not owned a Nikon but suspect it is quality made based on others opinions. I do own Leupold's and like them. I also own some Bushnell scopes and have no problem with them but they are not on my primary hunting rigs...just my personal opinion. Good luck in your pursuit.