If you were expecting important major design changes from last years model you will be disappointed. From the front view is basically the same design as it was on the S8. The only and most important difference is in the placement of the fingerprint sensor, which is now below the camera and not sideways.
Sizes are still the same for the Galaxy S series duo, the S9 and S9+, with 5.8" and 6.2" screens and infinity display. It's still AMOLED with a resolution of 2,960x1440px and an 18.5:9 (2.06:1) aspect ratio with 568/531ppi. As we expected the images on the display are well saturated, sharp and crisp as we expected from Samsung.
The camera is another feature that differentiates the S9 from the S8 and the S9+ from the S9. It's still a 12MP camera, but the first smartphone camera with the new sensor with a variable aperture of f/1.5 and f/2.4. Slow motion at 960 fps is available also in the auto mode which will help you create slow motion videos even better than the ones from the Xperia. The S9+ has two cameras now, borrowed from it's bigger brother, the Note 8.
Another important upgrade from the Galaxy S8 is the dual speakers system that improves the power and the sound quality with 40% on the S9. Software is another important upgrade for the Samsung Galaxy S9 that comes with Android Oreo out of the box. Bixby is still here and still has it's dedicated button.
In therms of hardware the S9 and S9+ both come with the Snapdragon 845 processor from Qualcomm or the in-house built Exynos 9810. The difference between the S9 and S9+ is that the 6.2" model comes with 6 GB RAM while the normal version has only 4 GB. Internal storage is 64 GB for the base model and can go up to 256 GB for the most expensive model. The micro SD slot card that supports a maximum of 400 GB of storage kept its place on the S9 as well.
The headphone jack is still here and in an even more convenient place along with the Samsung Dex option that can turn your S9 into a PC. The price has been upgraded also to $720 for the smaller variant and $840 for the plus model and it will be available for purchase from 16th of March. Pre-orders start on March 2nd.
The final question: is it worth buying?
If you have an S7 or an even older model definitely yes, but if you still have your S8 then...No. Unless you are too annoyed by the position of the fingerprint sensor or you wish too much to have that slow motion camera with variable aperture and the dual speaker system. Another reason would be the Samsung AR Emoji that are made famous and borrowed from the...Iphone X.