I had both 8x/10x 42mm SLCs. Still have the 10x but sold the 8x. Truthfully, I regret selling it. The optics of the 8x42 SLC are superb, very sharp and bright with great depth of field and deeply saturated colors. Although they aren’t flat-field it is a view I find very satisfying. Overall they handle quite well but I’m really not fond of their very slow focus in a hand-held 8x glass. Now, that same slow focus is an advantage when using the 10x SLC on a tripod and trying to precisely focus to field judge a distant Mule Deer.
As a hand-held 8x glass the SFL is my preference. Both the SLC and SFL offer bright, crisp, deeply saturated, and easy views. Either is a joy. The SLC may hold a slight advantage in perceived contrast and the SFL in easy view and colors. While both handle very well and are a joy to use, the SFL has a slight handling advantage. But to me, the biggest difference is in the focuser. The SFL is much faster and smoother. Much easier to quickly snap into precise focus on the desired subject.
My 2 cents.