If you have looked through them and like them then you won't be making a mistake but the 12's are not necessary with a good bino.
There should be some place to try out the optilogics around you because they are based in Tn if my memory is correct.
I personally would be leary of buying binos I haven't tried so if you can't find any then the ones you are looking at are probably best.
My advice is to try and find some to check out and see for yourself,then get what you like.