As an S8 owner myself, I'm seriously considering upgrading but I'm holding back because I think there is going to be some seriously interesting stuff on the horizon. I'm glad they are improving the low light performance because it's actually sort of bad on the S8 when compared to the iPhone 8. But I really just want more for my buck, the design language is too similar and the other features just don't interest me. I might upgrade to an S9+ if there's Samsung Pay incentives though. That's really the only thing keeping me in the Samsung ecosystem.
RE: Samsung Galaxy S9 Best Feature.