It's a personal choice, but I'd take an 8x over 10x....
An 8x will have better resolution, larger FOV, larger exit pupil, brighter for longer in twilight, have less image shake, and easier on the eyes for extended glassing sessions.
The only benefit to a 10x is better "twilight factor", and of course, higher magnification.
Personally, I much prefer my 7x42 Ultravid for all around use. Fewer glass elements than both the 8x and 10x, a larger exit pupil, less image shake, and a HUGE FOV. A quality 7x is like looking through a picture window. For strain-free glassing, absolutely nothing beats them! IMHO and IME, if more magnification is needed,....a lot more than 10X will be required! In which case out comes the BIG Eye binoculars (13x or 15x) or a good spotter.
