The only problem with manual controls is that 99% of the people you go up against are using full automatic controls and have a much easier time than you. I always get frustrated and in the end go back to default controls.
If you only play the AI it's all good though, as you say a well planned and executed attacking play ending in a goal is super rewarding.
EA should lower the default controls to at least semi, but I guess it's too late for that.
Yeah I'm not sure I'd be too comfortable going up against real players with manual controls. If I recall correctly it's fairly easy to save and switch configurations though so I'd mix and match.
I'm mainly excited for what it means for offline. I feel like I've been waiting YEARS for EA to make their offline modes interesting, and it turns out the answer has been right under my nose. Together with some of the other changes to Career Mode this year I can see me playing FIFA 18 offline more than on.