to answer your question, in my opinion
steiner are not worth a ham sandwich
zeiss are amazing
swarovski's are incredible
Leupold wind rivers are very good for 1/3 the money
Are they worth the money? depends on your finances! if you can afford to part with $1500 then I say yes definately. if spending $1500 will stretch you thin, then I say: no, buy a pair of leupolds.
Magnification? I like 10 powers personally, and always get as big an appeture as you can. Ie. 10 x 50 is better than 10 x 42.