I've owned both Nikon and Leupold glass over the years and never had a problem with either. Although, I believe the Leupold glass has a slightly sharper image. Admittedly, this point is arguable.
With that being said, I do own a pair of 10 x 42 Leupold Olympic binoculars. They are very rugged and hold up through a lot of abuse (or shall I say hard use.) The only thing I might change about them is the eye piece. I believe the design could use some improvement in that aspect. The eyeglass vs. non eyeglass wearer portion gets worn and gets to the point where it moves in and out too easily.
If I had it to do over again, I would've bought the Nikon's, but that is only provided they had a more robust eye piece than the Leupold's. The best way to compare is by visiting a sporting goods store and checking both of them out.
Hunting is not usually a pursuit where instant gratification abounds. It takes a lot of time, practice, resources and patience to be a successful hunter. So when someone decides that an area they hunted only once without taking an animal is worthless and devoid of game, I don't quite understand it. These people usually jump from game management unit to game management unit; trying a new one every year.
Now don't get me wrong, there are people that just enjoy scouting and hunting...