Josh, I have the Nikons and they are a decent glass for the money. I haven't had any problems with mine in the two+ years I've had them, other than my eyecups sticking a bit. I used them on a 20 day float hunt in Alaska where they saw the entire gamut of weather, including a brief dunk in about 2 feet of river water. Myself, I don't think they match up to the big three, but that's just my eyes. Yours may see something different. I can't speak about the 12X42's since I haven't used them, but would assume you will need a tripod to keep them steady. I like the 10X as a good all around bino. Unless you can't/won't spend the big dollars on the big three, the Nikons are a good bino. I would recommend them for a low to mid priced bino.
Good luck,
Garion