I'm right now looking at a similar situation. I was planning to get the Note 8, but decided to wait for new lineup announcement - worst case scenario it would have dropped the Note 8 prices - and it did.
I can give you my thoughts on the subject, from the perspective of future buyer:
Note 8 is a class in on itself - larger screen + improved multitasking (which is again easier because of the larger screen), has a stylus which lets you scribble on the screen without turning it on (big plus for me), has dual sim (again useful if you dont want to carry work phone about), dual camera. The big minus is an ancient single-speaker-to-the-bottom setup, which annoys me greatly as a past HTC One user.
S9 (and S9+) is new, so better android support from samsung (they drop the ball extremely quickly), better low-light camera, stereo speakers (finally, though with an odd setup) aaand that's about it.
They both have the bixby button, which majority of users hate, as it's an inferior google assistant basically. I believe samsung will keep pushing bixby updates to all devices - if for nothing else, just to keep disabling the button remappers
If you can't wait (the missing the phone part im assuming) think whether you value the stereo speakers that much - thats the 191 quid premium you would be paying. Note 8 is already a massive upgrade over s8+.
As for myself, i will wait for note 9, hoping for stereo speakers reaching the mastermultitasker.
AlmostNotable got a reaction from Lurick in Samsung S9+ or the Note 8?
