s9 plus upgrade or note 9

In my honest opinion, don't waste your money on Note9. Might as well wait for Note 10 or S10 which will be 10th anniversary(of S series) phone from Samsung so expected to come with great deal of upgrades both software and hardware wise.
Besides Note 9 doesn't offer that much of upgrade over Note8 except S-pen, ultra slomo, minor upgrade in processor, AR emoji, stereo external speakers, 0.1inch larger screen, shifted finger print scanner and few minor tweaks here and there.
Rest is your wish dear.

Same reply as before. I have Note8 and my wife has S9+. I hardly get tempted to upgrade, Because there's nothing major upgrade to spend for. Trust me save your money for 10th iteration, you won't regret.
Also Samsung NOTE8 even after 2 years of use will at least give you 25ks so at that time you can exchange for new device with major upgrade of course and you will have to pay little more than if you do it now.

wait for s10 launch dont buy note 9

you will get best features in s10 series than note9
100% there will be in Display finger print scanner
triple camera on rear and dual camera in front
5g connection
screen to body ratio up to 92%
more powerful processor
and even more

Thank you for reaching out to the Samsung community! We would like to inform you that the price may vary while exchanging the device and same can be better clarify by Samsung online shop team. Kindly visit this ink:- https://shop.samsung.com/in/contact/ and choose the mode of contact with Samsung online shop team.

Be sure to hit ♡ when you find an answer that works for you. For further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/