as far as quality, I hear great things about Trij and Mepros. I agree with CMOS, and use Mepros for the same reason. If you just want good sites, that you can see well day or night, then I say Mepros by a slim margin... If you're looking for different colors, adjustables, something other than 3dot, or any other specialty item, then you're opening up a can of worms that ends up being your personal preference.
Clear as mud? Kinda figured....
