8 is going to be important in seeing if any changes have been done to overheating and battery life. If it's only something like a 5-10% improvement to battery life then 9 will most likely be the same if still using Exynos infrastructure.

Love photo sphere but it's too slow in most applications

It's been so unreliable lately especially when using Waze. Plus reporting via voice on Waze hasn't been working for ages. Add the intermittent disconnections and I'm tempted to buy a cheap iPhone for Carplay when driving