I wrote a review on the 10x42mm HD here:
https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/11185521/Re:_Euro_HD_review#Post11185521
I haven't used the 15x56, but this line from Meopta I'm has amazing quality at a great price. I found the 10x42 very close to the comparable SLC HD, can't see why the 15x56 wouldn't be similar.