I hunted with a very light, 22 oz. 9X35 B&L fpor many years. Would not buy a 10X40 Zeiss Classic because they were just as good, but not water proof.
Finally broke down and bought an 8X42 Leica and was astounded at the sharper image and hack eye strain. Took several years to realize that it wasn't so much a difference in glass quality but a difference in weight, the Leica weighs 34 ozs.
I have no doubt that a like weight 10X40, like
Cabela's Euro, would give my Leica a run for the money.
I hunt everything from the vast open areas to the thick stuff of our second/third growth forests. I have three 8's, the above 8X42, a Pentax 8X40 SP for "casual use" and an 8X32 Nikon LX. I'd let go of my 12X50 Leica BN's before I'd let any of them go.
I've also got some much cheaper 6X30's and one 6.5X32. Those I use a good bit as well. But not the old 9X35's and seldom do I use the 12X50's E