Hi Josh -- I've been using the Shogun Flame with the A7sii for about a week now. It's been a pleasure to finally be recording a higher bit rate image using s-log 2 & 3, I no longer worry about banding issues which was a constant battle with the internal recording. You're getting a 8 bit 4:2:2 prores file that is ready to throw into your NLE. Big time saver for my work flow.
At the end of the day the biggest pro is the fact that it's a great monitor, you're able to properly expose your image and see a preview of that image. It's also a great screen that you can see in direct sunlight... Highly recommended, although it's a bit tough to swallow the additional expense on a $3,000 camera. It's an investment in your kit that will help you capture great images into the future.