My initial impressions:
Coming from the S7 Edge, this phone is 10,000 times faster. I literally cannot believe how fast it is loading a webpage and switching between apps.
The battery life so far is amazing. I've been using it all morning and it's down to 95%. My S7 Edge would be at 60% right now.
It's a big phone but feels good in your hand. One handed usage is difficult but manageable.
The facial recognition/iris scanner is blazing fast and much better than the previous fingerprint on the S7 that literally never recognized my fingerprint.
The screen is big and bright, but for some reason I feel like the colors were more vibrant on the S7 Edge. I'm not sure if there's a setting I need to tweak, but the colors don't "pop" as much on the Note 9.
Bixby is more useful than I imagined it would be. Still getting to know it, but I like it more the OK Google that never worked for me.
All in all, a massive upgrade for me. Loving it so far!