I have owned 15 swaro's, and they are nice binoculars, but I still find myself using my 10x42 el's considerably more. So much, that I got rid of the 15's. The image is just not as crisp, and no where near as bright. I doubt that 15 HD's will compare to the 10 hd's. Exit pupil is smaller = less light. I am curious to look thru them, but not expecting a dramatic change from standard 15's.
Let me know what you think when they come in. I might consider changing my mind and buying another pair of 15's.