Rolling shutter is the same and the price is too high compared to the A7s. I know they add a new Slog feature, but those things are pretty minor.
My friends already have handheld stabilizers for their older models. The internal 4K would be the only reason I see to upgrade, but since my A7s was $1600 new, the $3000 price tag puts it out of consideration.
Pardon me, but this seems rather ignorant for me. Every new feature, taken appart might be an upgrade reason for a serious videographer, let alone the whole package.
S-Log 3 provides additional lattitude, while the camera has superior colour to a7s which was a serious problem for many people. And you start @Iso 1600 with S-Log.
Around half a stop better high ISO (not like the original a7s was bad).
5-axis, there are situations when you need to hand-hold the camera, not all people have stabilizers.