I haven't tried them as I already failed miserably on world class and went back to professional with my tail tucked between my legs!
Started the season on World Class for the first time, beat Arsenal 3-1 in the Charity shield so thought hmm not so bad, next match Man City, lost 6-2, next match, Newcastle home, was losing 5-1 when I accidentally turned the xbox off

So now I'm back to professional but 100% manual including no auto switching (got the achievement yay!) lowered pass error for both teams, enjoying it much more, teams I should beat I'm beating (example Stoke who I played twice in the space of 3 days I beat 4-1 and 3-0, against Man Utd I lost 6-2 but I played really badly so no complaints), Champions league is going great so far, Marseille I beat 3-0 at home then Bayern Munich 2-1 also at home, early days of course.