I have both an SM-G930F and an SM-G930U here. The U model should be comparable to the A model in terms of its processor (maybe a little faster due to the lack of bloatware). I can tell you that between these two devices, the F model is noticeably more snappy as far as how quick the screens load and refresh. This is likely due to two reasons. One is the faster exynos 8-core processor running at a higher clock speed. And the other is that it's my understanding the exynos-equipped S7s hold previously loaded apps in cache for quick access. Whereas the snapdragon-equipped S7s reload the apps each time. That's what I've read at least.
One of the ways I can easily see the loading speed difference is to go to Settings > Applications > Application Manager and watch for scroll latency when I immediately swipe to scroll the apps list. On the F model, it almost never hesitates. But on the U model it absolutely always hesitates, lags, then finally catches up and scrolls smoothly from that point forward. Both devices have virtually the same app lists. The exynos is noticeably faster.