I mean you can always turn it off for a week and see how it is. Then turn it back on for a week to compare. It's the only way for you to decide since it's your phone.
This is a very interesting idea. I’m actually going to try it for a while and see how it works out. So far, in my incredibly limitited testing, i REALLY like it turned off.
I turned predictive text off the day they released it. The combination of the edit tools and the predictive text bar causes the keyboard to take up nearly half the screen!