I have come to the conclusion that the differences between top end glass, from an optical standpoint are more illusory than real. They all offer all of the resolution that the eye can use. So does the much less expensive ZEN ED. What is more critical to me if you are going to layout $$$$$$$$$ for a top glass, you need to decide first off what magnification you want. If you're a 10x guy I guess you have that part figured out. From there I think the decision needs to be made on how the binocular feels when you are using it. Each of the top brands has a little bit different look to the image. Some people will see those differences as significant. Others, like me could be happy with any. For example the Zeiss is usually a bit brighter in appearance, with a more white to blue color bias. The Leica excels in sharp images with no apparent color bias, while the Swarovski tends to be a bit warm in color bias and has an ever so slight tint. Same deal with the Steiner Peregrine XP. Now, I'm a certified cheapskate and do not feel the ZEN ED or Promaster ELX ED gives up enough to warrant what I'd have to pay for the difference. Having said that, if I was going for a top end glass, it would be the Steiner XP. Just because it has the right "feel, heft, or panache" or whatever you want to call it. So if you have been doing some looking and the Leica has shown you something you like, then that is where I'd advise you to go. It matters not what I like, you will use it. Don't let a buddy cajole you into a Swaro because he likes it. If you like the Leica, get it, use it, enjoy it and wish the same for your friend with a Swaro or Zeiss. You will all have what you like.
