Ernst Abbe of the "Abbe" in Abbe Koenig was co owner of Zeiss way back when, so the design has its roots in Germany, it is a popular albeit somewhat heavy design so these binos typically weigh more than their Schmidt-Pechan brethren which has largely taken over the high end market. Some would argue that the A-K design offers better light gathering ability than S-P designs; however, the aforementioned benefits of size and weight of S-P have all but erased good A-K designs from the market.
Vortex has one of the best warranty's in the business, no questions asked, ever even for accidental damage. In the optics world you pretty much get what you pay for, so it's likely the Vortex UHD might be a bit better optically just due to the price difference.
Other binos to consider under $2k would be the Kowa Genesis 10.5x44, Zeiss SFL 10x40. One other thought, you can often find used Swarovski EL 10x42's for under $2k (but make sure they are the "newer" EL with Swarovision because if not you might as well get the newer SLC HD design), these are pretty much the best of the best for the price. Kowa has the best glass I've seen to date compared to European glass (though I haven't seen everything), I'm going to be testing the new Vortex UHD 8x32 binos that were just announced so will be curious to see how these do.
www.sigsauer.com 
