Point to ponder regarding binos...the second number is the objective lens in mm, the first is the magnification.
The second number divided by the first, therefore, gives you the exit pupil diameter in mm, which tells you quite a bit about the amount of light they'll make available to your eye.
An adult human pupil probably won't dilate much more than 7mm, which is why you've probably never seen anything bigger than 7x50, which are great for scanning and light gathering.
If you're always looking during the day, 7x35 is probably pretty good. Most people can't stabilize much more than 7-8 power of magnification, so for most people, increasing the magnification doesn't really improve the view that much, it just narrows the field of vision. My good binos are 8.5x56mm because I happen to be pretty good at holding very still but you'll notice the ratio of 56/8.5 is pretty close to 50/7.
Anyway that's just general commentary on binoculars, but potentially food for thought. I like a lot of light gathering power just in case I'm using them at dawn or dusk, myself.
The best source on binos I can think of offhand is the Cornell department of ornithology.
I use Nikon ATBs but I have dealt extensively with Vortex on a professional level and the description of their warranty is accurate. If there's something wrong with a Vortex anything they'll replace it on the spot. I use a Vortex optic as a reference optic for work, actually. I'm not an expert on optics but I do have to use them a lot.
I don't know what the Nikon warranty is like.
