Well since the difference between 1st n 2nd focal plain has been explained, i like the fact that with the 1st focal plain scopes i can use the reticle on any power setting to range with the reticle, it is no use to me to have to use the scope on 12x to range when the light is so low that i find i can see better on 8x. Also with the 1st focal plain scopes there is absolutely no dangerof a wandering zero when you go up and down through the X's, most good quality 2nd focal plain scopes will track through the magnification ok, that is most shooters and most rifles will not be capable of noticing any deviation, but simply knowing it is possible for the scope to wander the zero does not instil confidence, i have seen examples of the best makes which would shoot a different POA at 6x, at 12x and anywhere in between. That doesn't happen with a 1st focal plain scope.
When it comes to optical quality and reliability we are all to poor to buy a cheap option,like i said before, The after taste of poor quality, or for that matter, unreliability lasts a lot longer than the joy at buying for a bargain price.
Luckily the difference in the price of the S&B and the Zeiss, Swarovski isn't all that much, and here in Europe its cheaper than the NXS due to import duty.
Me i want a scope i can trust my life to, and you owe it to that magnificent game animal to trust its life to it also.
which ever scope you decide on, test the thing, test it test it and test it some more.
Pete