I ordered FIFA 18 from Flipkart and was excited about playing it on my PS4. I was playing FIFA 17 before that. FIFa 18 was a huge dissapointment considering you already have FIFA 17.
They have completely changed the gameplay techniques and also the game speed. You will have to get used to it. Graphics wise it is definitely better than FIFA 17.
But if you already have FIFA 17, I would recommend you stick to that and not buy FIFA 18. Infact invest in some other game like Don Bradman Cricket 17